Upgrade SQL Server 2012 Express to Evaluation Edition Is there a way to upgrade an instance of SQL Server 2012 Express to SQL Server Evaluation Enterprise?

I tried using the SQL Server Installation Center and clicking Maintenance, and then Edition Upgrade. I selected to upgrade the Express Instance to Evaluation, but I get an error on the Edition Upgrade Rules step, which says "The selected SQL Server instance does not meet upgrade matrix requirements." I also checked out the Supported Version and Upgrade Paths on Supported Version and Edition Upgrades and Express 2012 to Enterprise 2012 is supported, so it would make sense that Express 2012 to Evaluation Enterprise 2012 should be supported especially since they are both free and Express has less features than Enterprise.
Am I doing something wrong? Is there a better way to perform this upgrade? Thanks,
You can not Upgrade from SQL Server Express Version to SQL Server Evaluation.

See this msdn link for all upgrade path...

Supported Version and Edition Upgrades...

Install them side by side and they you copy wizard to move DB.