Conversion issue in alternate UOM

Hi,

we are facing one issue. in material master we need to the following conversion ratio 100000pc = 499 TO (MT). We have to put so big quantity for pc as system is not accepting fraction of TO in left hand side in form of decimal.

Now if we put the above conversion factor, system is not accepting that giving an error "Entry is too long (enter in the format__,____".. Actually system is allowing us to put upto 10,000.

How to change the allowed input field length for alternate unit conversion ratio field in material master.

Regards,

Santosh