That should be possible. Worst case, you can use the Excel macro to feed keystrokes to the other program. I haven't done this more than to test whether it was possible when we had bought another business and needed to import their data to our system. Fortunately, a better method was found (always knew there was a better method; we were worried about the price reflecting it!) so I didn't need to brush up on this aspect of VBA.

To do this is pretty intense though. You are actually doing Windows programming from within Excel. You need to be aware of whether the program is already running and whether it needs to save data prior to your macro manipulating it. My advice, get a good book. I recommend John Walkenbach's Power Programming with VBA as one good source.