Question About User Service

Is there a way to specify a particular Group to which a new user should be added when using the User Service?

I was hoping that something like the following might work:

http://example.com:9090/plugins/userService/userservice?type=add&secret=bigsecre t&username=kafka&password=drowssap&name=franz&email=franz@kafka.com&group=mygrou pbigsecret&username=kafka&password=drowssap&name=franz&email=franz@kafka.com&group=mygroup

TIA!