What I'm to accomplish is I want to have my assembly open and one by one select the 1st part and make it the work part.then run piece of my journal and save. Then select the next part and do the same and etc.
There is an article here that shows how to step through all the parts in an assembly. You can record a journal while making a component the work part to see what code is necessary to set the work part. Incorporate the recorded code into the code from the article to get what you want.