"Convert" Case into an Opportunity

Hey good folks!

Scenari: Case is created from an email from client. It happens to also include a sales opportunity.

Best way to "convert" (well, actually create an Opportunity from the case and copy the email over to that Opportunity) it to an Opportunity without too much/any coding?

Workflows depend on criteria but in this use case, a human needs to decide so...

Thanks,

KGM