Thanks again for the response, Brian.
It's actually a very useful tool for clients, so I don't know why they would leave it out either.
With regards to me creating something, I was concerned that any table or field name change via a WHMCS update could potentially break anything I did, so I didn't even attempt anything. I think I'll read up a little about how to develop for WHMCS before even going there. I'm well versed in PHP and MySQL, but unfamiliar with WHMCS in general, and if I'm honest, the BASE64 code in the admin functions for the billable items just made me assume it was better left to those that are more familiar.
Anyway, thank you again for looking into this, and have a great weekend.
Kindest regards
Warren