I have seen plenty of VB6 examples of EditStreamCallback using EM_STREAMIN/OUT. Here's one from this site:

http://vbforums.com/showthread.php?t=336077

However, I've yet to see one for .NET anywhere and I really need help setting it up. If I could get some help I would greatly appreciate it, please use Notepad as the example external app.

I just need to get text and set text in a form on an external app and WM_GET/SETTEXT don't work because it's a Rich Text form... I am already familiar with basic API functions like FindWindow, SendMessage, and PostMessage, but I'm clueless when it comes to EditStreamCallback... Please start from square one if possible.