Thanks Kyle - we're on the right track. Can I include logic and formatting into the script?
For instance, can I bold one attribute?
Also, can I append each line onto the label block only if one attribute is non-zero? What I'm labeling is percent ownership of the polygon feature ... some polygons have one owner - others have more. A problem I am facing is that polygons with one owner have empty Own2, Own3, and Own4 in the attribute table, but Pct2, Pct3, Pct4 have 0 ownership percentages which are treated as labels anyway. In the clumsy approach I was taking before learning from you, I suppressed those labels using classes.