Windows XP – DOS program issue

I recently installed Windows XP in our office and we run a DOS accounting program. The program works fine, it’s just that I cannot adjust the size of the fonts that the program comes up in so it is very hard for people to read. I’ve tried adjusting through compatibility mode making the screen full-size, changing the font size, but the font always stays the same. Am I just stuck with this or is there somwthing I’m missing?

Thank You.