Dynpro Inputfield format

Hi folks,

Most likely this is just a simple question but I just can't find an answer:

I have a Dynpro with an input field of type quan and a global variable of type quan13. Because auf this you can enter numbers with three values after the komma ie. 4,002

I'd like the user to enter just whole numbers. I tried changing the input field to NUMC. That worked for the input field but resulted in a wrong value in my global variable. For instance I entered 4 and got 0,004 in my variable.

Any suggestions?