Thank you for your comment Kirk.
What I want to do is change all or a subset of photos in a contact sheet. Assume one of the photos has a name of the form JLB_2010-10-15_003.NEF and I want to reset the 003 to 001 and have the balance of the photos follow as 002, 003 ... NNN. I select all the photos and then select JLB_2010-10-15_003.NEF in preparation to making changes to all the photos. At this point something like JLB_2008-01-15-02_057.NEF will show up in the window directly below "Please enter the photo renaming string:" which is the name of the last photo I was working on in another contact sheet. What I would like PM to do is pick up the name JLB_2010-10-15_003.NEF under "Please enter the photo renaming string:" and allow me to reset the variable to "001" and hit rename. Instead I have to edit JLB_2008-01-15-02_057.NEF to make it like JLB_2010-10-15_003.NEF before I can make the global change to the variable portion of the name.
I was not that clear on my original formulation and I hope the foregoing is not too tedious.