Codematic Excel developers logo
Codematic spreadsheet-excel development image

Rapid Application Development / Advanced Excel Development

Products for Excel
Commercial Products:
  - Classic Ribbon
  - Alt-FileSearch
  - Password Remover
Spreadsheet Quality Products
Free Products
Excel Development
Excel Development Index
Excel VBA
- VBA IDE (editor)
- VBA Training
- VBA Best Practice
- VBA Performance
- COM Performance
- VBA Security
Excel and Databases
Excel and Pivot Tables
Excel Add-ins
Worksheet Functions
Excel and xlls
Excel (in)security
Excel testing
Excel and .net
Excel External Links
Excel Developer Types
Professional Excel Development
Excel 2007
Excel 2010
Excel Development Archive
Spreadsheet Services
Spreadsheet Development
Spreadsheet Migration
Spreadsheet Maintenance
Spreadsheet Review
Spreadsheet Management
Excel User Confs
Consultant Profile
Book Reviews
Site Map

Excel DDE Links

'Normal' links in Excel are worksheet cell to worksheet cell, or name to name etc. These are covered here.

This page covers the other type of link, the not so common one.

Dynamic Data Exchange (DDE)

This is a pretty old technology these days, well over 10 years old. In general Microsoft now seem to recommend developers choose a different technology for exchanging data live between 2 disparate applications.

Regardless of advice to the contrary there are many applications that make their data available to Excel via DDE. Most of the market data providers (Reuters, Bloomberg, Platts etc) provide DDE access to their data.

If you ever see an unusual formula something like this:


(notice the pipe character | ) If you see this. then the chances are you have DDE links to another application.

The basic formula structure is:

Program name | topic ! Field

If you would like to try out DDE links, we have written a DDE server that makes available data you can consume in a spreadsheet cell.

Its a very simple VB6 app:

Excel DDE server application

It provides 2 pieces of data (or fields in DDE parlance) the time and a random number. If you double click the formula you can paste them directly into a cell and see them update as you play with the form controls.

You can use Edt>>Links>>Update to refresh the worksheet cell values if they get out of sync with the app. This seems to happen more when the workbook has lots of links.

If you close down the exe and try to update the links you get this warning dialog:

Excel DDE Application not available warning

This 'Remote data not accessible' warning is the equivalent of the workbook not found error when trying to update normal links. If you click yes then Excel will try to start the exe via DDE. This will only work if Windows knows where to find the app, and it gives up fairly easily with this:

Excel DDE app not found warning

To make sure Windows can find the app (which should run fine from anywhere, on Windows XP), you need to add its location to the 'path'. this is the list of folders Windows looks through when searching for executable files (exe and dll).

You can add paths the the PATH by right clicking 'My Computer'>>Properties>>Advanced>>Environment Variables, then click path, then edit then add your new one on the end with a semi colon ; to separate it from the previous.

DDE link formulas in general keep their last known value, even when the source data application is not running. They do sometimes briefly go to #N/A whilst waiting for a response, especially in Excel 2007 and 2010.

To know if you do have DDE links you can look in the Type column of the Edit>>Links dialog for anything that isn't 'Worksheet'. To find where they are used you can do a find on the pipe '|', or use the Codematic Link Manager Tool (commercial version).

Download The Codematic DDE Server here.

Codematic Link Manager

Rich control and management of external links has been an important feature of so many of our consulting assignments we developed a utility to help. That utility has now been refined into a commercial grade Excel add-in, more information is here.


If you require any more information please get in touch.



Upcoming Events:

25 January 2012 - UK Excel Developer Conference - London

Products for sale:


Office 2007 FileSearch replacement logo

New information about the missing FileSearch feature in Office 2007 and details of our pragmatic solution (Current price GBP 30.00)


worksheet password remover logo

Instant Excel worksheet protection remover and password recovery (Current price GBP 15.00)

Classic Ribbon Tab

classic ribbon for office 2007 logo

Add Excel 97/2000/2002/2003 compatible menu structure to Excel 2007
(Current Price GBP 10.00)


Products coming soon:

Link Manager

(Find and control external links in Excel Workbooks)

Due by Q1 2111.

XLAnalyst Pro

(Excel VBA based spreadsheet auditing tool)

Due before the end of 2111.

This page was last reviewed on December 21, 2011

©Codematic Ltd 1999-2011