How to create a Wildcard SSL Certificate in CPanel

Short answer is "you can't"

The longer answer is "you can't - with cpanel, but you can with WHM"

If you are a reseller, you should have access to WHM which contains an option that allows you to create a SSL CSR and Certificate.

That facility lets you create wildcard SSL CSR's where the standard cpanel interface won't let you.

I know those details are sketchy, but if it is a case of you only have access to cpanel, you need to chat to your hosting provider to see what they can do for you.

On a side issue, I'm getting itchy feet about my hosting server again. I dislike the lack of control I have with this server, HOWEVER my next move will be to a dedicated hosting server that I can completely manage. Call it a goal I guess.