Rename .pdf files in a folder

Hi,

I am looking for a macro to rename the pdf files in a folder.

Say I have 100 pdf files in a folder 1-100, I need to rename the file to the list I have in excel. For example file name 1 should be renamed to "invoice 1" which I have it in excel spreadsheet. Similarly file name "2" should be renamed to "Invoice 2".

Please help!

Regards,
Vijay