Well, the solution was not all that forward, but after a LOT of trial and error, this finally worked:
I turned off all clr options (set them to no support in visual studio). The the setting for Dynamic Debug DLL needed to be changed to Dynamic no debug (no DLL). After that, it was just a matter of commenting out Stdafx.h and setting and current setting incompatible flags to compatible.
The project built into a normal .dll and is now working fine :D