I have an Excel VBA sub that (among other things) pastes a lookup formula into some cells. The lookup formula is presently of the form LOOKUP(RC5,lookup.xlsx!Item,lookup.xlsx!R2C:R559C) but the size of the lookup table will change. Is there a good way to find the size of the lookup table, that is, the last row? In a pinch I suppose I could open the lookup file (what's the command for that?) and do Windows("lookup.xlsx").Activate last = Range("a65536").End(xlUp).Row Windows("whatever.xlsx").Activate but I'm not sure if there's a better way.