Well, Win Xp doesn't allow user input from Batch files (it used to be done using "con").
You have two options:
1- If you have an interpreter(Python, Qbasic,...) I can easly write you a program that does the job and then write a batch file to run the program(makes it easier for the girl)
2- I can write you a program in C or C++ and give you the source as well as the executable (so you know that I'm not trying to hack you
)
Now I have some free time so I don't mind coding in either Qbasic or C++ but I'm rooting for option two because it is easier and it result in one file instead of two, what do you think?