This page will let you know which bodygroup-index you need, based on the bodygroup setup in your .qc file.
Just paste the $bodygroups from .QC into the field below. In the same exact order!
Then check/uncheck the desired body-combination that you want.
In the end, the "Result index" will show you which body-index you should use.
This can be applicable in your map, like:
ent_fire model SetBodyGroup X (X being the body-index)
CSGO/vscript has an already-included function which works:
modelhandle.SetBodygroup(int groupIndex, int value) ('groupIndex' being the bodygroup-index, 'value' being the sub-body index, indexes start at 0)
Note: make sure to follow the format of the ".QC example snippet" below, or the parsing may fail.
Thanks to Moltard for figuring out the calculation-formula (click here to view) Vscript/.nut variant (click here to download)