Excel Certification

Hello;

I heard once that there is an online test someone could take that would give them a certification for Excel - I'm not sure if this was through Microsoft Office or not - but my understanding was you could take the practise tests for free then pay for the real test and get documentation that you were certified.

Reason I ask is a couple people on my crew have been learning Excel; something like this would be great to put on their resume if they ever wanted to move into a new position.

Thank you!

Mike