Assume:

1. Launch Excel. File > Open "Test.xlsm". From Excel, File > Open "Test2.xlsm". From Excel, File Open "Test3.xlsm"
2. Start > Launch new instance of excel. File > Open "Test4.xlsm", File > Open "Test5.xlsm".

1 instance of excel with 3 "open" workbooks, another separate instance of excel with two "open" workbooks".

How do I properly identify each of the files for manipulation?