I want to find a program that can generate codes for C:\code1n 4-?

I currently have a program call "code1n" that runs on ms dos. This program spits out codes that starts with a "1" What I need is to know how to change the program so that it would generate codes that start with a "4". Example: from C:\code1n 1-xxxxxxx-xxxxxxxx-xxxxxxxx to C:\code1n 4-xxxxxxx-xxxxxxx-xxxxxxxx.