[sOLVED see my second post] After much reading I still can't figure out how to run an excel macro. here is my problem 1-excel book1 already open 2-personal.xls (with several macros in it) running in the background as add-in (invisible) 3-autoit should call macro "compare_files" in module 4 of personal.xls and run it in "book1" I try some code found here but get an error (see below) --------------------------------------------- WinActivate("Microsoft Excel - Book1") WinWaitActive("Microsoft Excel