BOM if...then help please

I'm not sure this is possible but I'd like to do thefollowing:

In the quantity column in my BOM I want to show the amount (feet,ounces, etc) of an item used but only if that value is not blank inthe part or assembly, if the value is blank then I can to use thequantity of the item in the assembly.

So basically...

If (Amount <> "") Then (cell value = Amount) Else (cell value= Quantity)SolidworksBill Of Materials