That's a nice dream, but impossible to make. You could do it only by making two different engines, which however can use the same assets when possible. If you try to put both low end and high end stuff into one engine, then both parts suffer, and the engine would be bloated with useless stuff too, even the source code.
Dude, you need to pluck your head outa that LE hole you've got it permanently stuck in... have a look around you may be amazed what programmers can write with these newfangled computer languages there usin today...