Now I see what you meant. That really is a nice feature to do something like "winecfg vd=1024x768".
I'll see if I can understand how winetricks accomplish that.
Winetricks is a simple script that adds a few mssing things to wine, e.g. it's how most people install ms dlls or .net on wine. It also provides a simple commandline way to change a few settings. For instance, winetricks vd=1024x768 sets a 1024x768 virtual desktop... it'd be nice if one could instead do winecfg vd=1024x768 or something like that.
See also http://winetricks.org.