Whipping cream that has been frozen won't whip
Sorry, no. 

Whipping cream that has been frozen is perfectly fine to use in many dishes, but it won't whip.

As far as I know, this is irreversible, so no, you can't make the cream "whipable". If you are very lucky, you will get it to a sort of semi-stiff stage, but nothing that would be suitable for cake decorating or similar.



Not part of your question, but possibly interesting for next time:
Whipped cream can be frozen, so if you have leftovers, you could pipe little tufts or similar, freze them and use them to decorate desserts.