Help with renaming files

I have a rule that watches a folder for a CBR (comic) file, then converts it to a CBZ file.
Here's the rule:
Extension is "CBR"
Do the Following:
Unarchive
Archive
Rename with pattern: "name".cbz
What I'd like to do is retain the original name of the file. The problem I'm having is that many of the CBR files were renamed. The CBR file may be "Happy Day.cbr" but when it's unarchived the folder is named "Happy Day (blah blah blah)." When my Archive action is run, the resulting file is "Happy Day (blah blah blah).cbz" because it's using the name of the folder when unarchived, not the original filename.
Any ideas how to store the original filename to be used during the rename function at the end? I've tried playing around with it, and I haven't been able to figure it out.
Thanks!
Here's the rule:
Extension is "CBR"
Do the Following:
Unarchive
Archive
Rename with pattern: "name".cbz
What I'd like to do is retain the original name of the file. The problem I'm having is that many of the CBR files were renamed. The CBR file may be "Happy Day.cbr" but when it's unarchived the folder is named "Happy Day (blah blah blah)." When my Archive action is run, the resulting file is "Happy Day (blah blah blah).cbz" because it's using the name of the folder when unarchived, not the original filename.
Any ideas how to store the original filename to be used during the rename function at the end? I've tried playing around with it, and I haven't been able to figure it out.
Thanks!