Do you mean you have numeric fields and you want a proportional value in you ouput row, based on the area of the shape after clipping? Are you working with shapefiles or geodatabases?
No idea, sorry. But I'd be very keen to hear the answer.
MapInfo can perform a field calculation which works out the proportion of a numeric field based on interesecting shapes
I can only think of adding a new shapearea field, then looping all numeric fields and recalculating them.