Use VB
Beleive it or not, you can write quite complex programs in DOS with Visual Basic... just not the new versions like VB-6 or VB.NET.
I think that you have to find a VB-3 program, to program 16-bit applications. All versions after that write files in 32-bit file format (which only work for windows). Good luck on finding a VB3 disk now days though...
But E-bay is God when it comes to rare and discontinued stuff. So try there. I wouldn't think it to be TOO expensive since it's so old...