I understand what you are saying
I only want to print the store number on the top of the 1st page
In the rules guide it says to put that code in the onjobstart and you can add variable which is what i did.
FusionPro's imposition system supports specifying the slug line in either the FP Imposer GUI or in the OnJobStart rule. When the slug line is defined in the OnJobStart rule, you’ll have the flexibility to not only use static text, but you can include variable data as well. For example,
FusionPro.Composition.impositionSheetSlugText = "Enter your slug text here.";
Please note that to turn on the slug line in the output file, you’ll need to select the Page Info checkbox in the Composition Settings dialog’s Imposition tab.