@Necrophear:
I'm currently modding the source, and believe me... you don't want to try coding a "LOADLEVEL=X" script command.
For starters, it would always have to load the player up at the beginning marker in the map, which wouldn't allow you to do what you're looking for anyway. And, the fact that I'm willing to bet that your second level's starting cell isn't in the exact same position as your first level's ending cell, you couldn't really tell it to go off of that, either.
The one and only,
~PlystirE~
Urlforce:
Dude, I'd rather be declared a dbpro noob than an fpsc legend any day!