How to exclude letters from scan output

I would like to exclude letters from my bar code scans. I have the 123scan software but am not able to figure this one out.

Example:

1-98562-7ah - desired output - 1-98562-7

98562-7a - desired output - 98562-7

1-98562-7a - desired output - 1-98562-7

Thank you in advance for your help.