Shorten Filename based on regular expression

Hello everyone,
I am new to Hazel but very excited about obvious unlimited capabilities. One of my first tasks is to create a rule to move and rename my mobile created scanned business expense receipts. I have the OCR task performed via PDFpen, the import to Evernote script working, but would really appreciate some assistance with the simple task of renaming the files.
In short, I am saving the receipts when scanning via my iPhone as "EXPLunch.PDF" to a Dropbox folder. The "EXP" string is my identifier for Business receipts versus other files. What I would like to do is strip the "EXP" off of the name once the Hazel rule runs and then rename the file as just "Lunch.PDF.". I am sure that this can be easily done, but it is escaping me.
Thanks for any help!
Adam
I am new to Hazel but very excited about obvious unlimited capabilities. One of my first tasks is to create a rule to move and rename my mobile created scanned business expense receipts. I have the OCR task performed via PDFpen, the import to Evernote script working, but would really appreciate some assistance with the simple task of renaming the files.
In short, I am saving the receipts when scanning via my iPhone as "EXPLunch.PDF" to a Dropbox folder. The "EXP" string is my identifier for Business receipts versus other files. What I would like to do is strip the "EXP" off of the name once the Hazel rule runs and then rename the file as just "Lunch.PDF.". I am sure that this can be easily done, but it is escaping me.
Thanks for any help!
Adam