enl to pdf conversion is probably searched by users that want to export EndNote content from .enl libraries, but this is actually not done as file conversion. You have to access the library in EndNote and export the items from the database as PDF files.
Quiet often these libraries (represented as .enl files) actually contain links to PDF files and other publications and you can check the link out from the database. You will always require EndNote to deal with .enl files though.