The image shows the graphical output of the enclosed test application.
This snippet demonstrates how to make a RichEdit control transparent -- so that the text draws over top of the contents of the parent window (or even a memory DC). Best of all, it should work all the way back to Win95 / NT 3.1 and only relies on the Win32 APIs.
The basic concept is to draw the contents of the control into a memory DC, then use BitBlt() techniques (or TransparentBlt() if available) to generate a mask and overlay the text directly over the target DC.
This code is hereby placed in the public domain.
DownloadsDownload demo project - 51 Kb
Download source - 3 Kb