could someone explain me how to make a qbw that (if pressed) calls *100#? which commands do i have to use?

thanks

Edit: I used this command :dbus-send --system --type=method_call --print-reply --dest=com.nokia.csd.Call /com/nokia/csd/call com.nokia.csd.Call.CreateWith string:"*100#" uint32:0

from here http://wiki.maemo.org/Phone_control

but it "calls" the number like a normal phone number, as it is a ussd request it doesnt work is there any command that requests ussd codes?
Thanks