The buildin database is not intended to be used on the production deployments. It's just a 'helper' so that Mendix can run out of the box without installing a database server.
So first suggestion: if you want to transfer data from PC to production and vice versa, never use built-in database. Personally I use the build-in database almost never (except for demo's, test projects, ..).
About the conversion: that's not possible without a complex database migration. The best thing to do is export / import or fill the data manually.