D&D 3.5 Masterwork Weapon Macro/Math Help

I'm trying to concoct a macro formula to put in a character sheet that will apply the greater of two values: either the masterwork bonus of a weapon (which will be either +1 or 0) or its enhancement bonus (which can be any number from -6 to +6). That above part is easy; the difficult wrinkle is I would like for a negative enhancement bonus to trump the masterwork bonus. This is for those cursed magical weapons that may have a magical -2 to hit - you don't get the masterwork bonus to hit. Short of a sheetworker or the API is this possible? I am sure it involves the abs() function somehow, but I have not been able to come up with something that works in all cases. Thanks in advance for any advice.

This should work: {@{e}, @{m}}kh1 * ceil((@{e} + 1) / 100) + @{e} * (1 - ceil((@{e} + 1) / 100) ) ceil((@{e} + 1) / 100) equals 0 if @{e} < 0. Otherwise, it equals 1.

Thanks very much for the math brilliance, Silvyre. It works exactly as I wanted. And clearly, I was barking up the wrong tree with abs().... d'oh!