The Visual Studio.NET application development platform does not support Dynamic Data Exchange (DDE) directly. There also appears to be no plans to incorporate DDE support into the .NET languages.
The best solution that we have found so far is an open source class library called NDde. The NDde class library is an extremely well designed Dynamic Data Exchange class library complete with sample code that shows how to use it as well as complete and well written user documentation.
You can download the NDde class library from the following web site:
http://www.codeplex.com/ndde
The NDde library comes with sample VB.NET and C# source code that demonstrates how to use it to create both DDE Clients and DDE Servers.
For connecting to WinWedge or TCPWedge, you would normally only use a DDE Client connection. DDE Client connections support both receiving data from WinWedge (or TCPWedge) as well as sending DDE Commands to WinWedge.
The following link can be used to download a ZIP file containing a VB.NET (framework 2.0) sample executable program (with source code) that shows how to communicate with WinWedge (or any other DDE Server) using the NDde class library. The sample program shows how to both retrieve data from WinWedge using DDE and also send DDE Commands to WinWedge: