Excel 2007 : Cell Format while editing problem

Not great with Excel and cannot for the life of me figure out this problem. I have tried formatting the cell with all the available options to no avail.

Problem: I have a number in a cell ie. 111-3-2, I want to remove the 111- and leave the 3-2. However when I do this excel converts the 3-2 to a date, if I format the cell to a number and then remove the 111- it converts 3-2 to 40604 etc... So how do I remove the 111- out of my number and leave the 3-2 without having excel automatically convert?

Thanks