I do not follow it all the way. Do you want to:
Check if Part1 was successfully selected with SelectByID2?
Check if the file Part1 is loaded in Solidworks?
Check if the file Part1.sldprt exist?
If the filename can be anything... then you should just get the name of the selected part and then process the update. However, if the user have selected wrong part, wrong part will be updated. A good thing would be if there is any properties to use in order to find out if the part is from the customer or not.
I want to Check if Part1 was successfully selected with SelectByID2. If Part1 is replaced by Part2 in the assembly, Part 2 would not be updated due to it not being found and updated by the macro, it would try to look for Part1 and then skip over the process because it doesn't find it. I want to eliminate the ability for the macro to skip Part2 by notifying the user that Part1 was not found. If you have any more questions, I'll be sure to answer them. Thanks
SelectByID2 return true or false depending on if the selection was succussful or not.
So if you evaluate your boolstatus you will be able to tell the user if it part was selected or not.
If boolstatus = False Then
swApp.SendMsgToUser "Selection failed"
Beautiful and simple. I like it. Thanks!