This is a typical problem and no different from Excel.
You will need three fields.
You already have the calculated field. Rename it to [Calculated Commission]
Then make a new field called [Commission Override]. Be sure it is not checkboxed to treat null as zero.
Then make a new formula numeric field called either [Commission] or perhaps [Commission (final)]
IF(not IsNull([Commission Override], [Commission Override], [Calculated Commission])
------------------------------
Mark Shnier (Your Quickbase Coach)
mark.shnier@gmail.com
------------------------------
