Thanks, Matti, for your quick response. Unfortunately, even CA3 does not seem to be the thing I am looking for, as it still seems to require several manual steps to open and select each of the required files and start the TAB/owc generation. If you have to do that 12 or more data files in a row you quickly start to loose concentration and make errors... That's why I'm still loking for a script based solution, which then can either loop through the files in a particular directory or reads the file names from a list. I really appreciate your offer to set up a sample VBA script to be used from Excel. Unfortunately I made a typo in my first posting: it should have read VBS instead of VBA - I don't have a developer's license, so your proposed Excel VBA script will probably not be able to call the OWC, will it? But if there's a way to start the OWC via VBS I would be grateful for some hints how to set this up properly. Thanks!