just tested it myself in Visual Importer and Advanced ETL Processor
Worked fine for me
Driver={SQL Native Client};Server=test;Database=demo;uid=sa;pwd=xx
Driver={Microsoft Excel Driver (*.xls)};DriverId=790;Dbq=C:\\test_data_source.xls;DefaultDir=c:\\;
But I do not think it is possible to open password protected Excel file at all
the driver itself does not support it
support.microsoft.com/?KBID=211378
Peter