am running rabidvwm.dll just nicely in lsbox.
all of rabidvwm settings are specified in step.rc (and none in *.box - well, except for: *ModuleHook !VWMLoadBoxHook).

here's my step.rc settings:
VWMLoadInBox true
VWMX 2
VWMY 0
VWMDesksY 4
VWMDesksX 1
VWMwidth 40
VWMheight 120
VWMDeskSpacing 10 10
VWMSnapWindowOnDrag true
VWMNoSwitchOnFocus true
VWMNoGathering true
VWMTitlebars true
VWMTitleForTitle true
VWMBackBmp vwm_back1.png
VWMSelAlpha 70
VWMSelColor C0BEBF
VWMSelBorderColor 000000
VWMWinAlpha 200
VWMWinColor ABABAB
VWMWinBorderColor 13181C
VWMTitleColor 216D94
VWMTitleBorderColor 13181C
VWMOnQuit !LsBoxSavePosition control.box

notice the VWMX and VWMY coordinates....