I got it to work. Finally. It's 3 AM. I made the change from XLS to XLSX which brought some extra, frustrating problems related to cell writing. I also had to install the 32-bit version of Microsoft Access Database Engine 2010 (I originally had the 64-bit version). Here's what I've done: #include <ADO_CONSTANTS.au3> $oMyError = ObjEvent("AutoIt.Error","MyErrFunc") Func MyErrFunc() Msgbox(0,"AutoItCOM Test","We intercepted a COM Error !"