You will have to change the Internal Field Separator: IFS
q='"Something, variable", another part, third one'
# save actual IFS
_old_ifs="${IFS}"
# set IFS to ","
IFS=","
# split q with this new IFS
set -- `echo $q`${q}`
# restore standard IFS
IFS="${_old_ifs}"
echo \'$1\'