recompiling dwm with custom config.h

[Béla]

Hi guys,
Anybody using dwm out there? I'm quite new to NetBSD... I want to
recompile dwm in pkgsrc with a custom config.h file but I have no idea
how to do this. Under FreeBSD it would be something like:
make DWM_CONF=/path/to/config.h
How do I get the same result under NetBSD?
Thx!
Béla.