John:
I use Ed Rauh's API_APPRun #974 in the files section. It's easy to use, but running a DOS app has the DOS window popping up at inopportune times, depending upon the platform. On some of the 9x platforms, you can turn the desktop off with an API call while the DOS app executes. The DOS apps I run in this manner are lharc.exe and some file format conversion utilities for a 3rd party comm product.
HTH
Mike