Its not easy to just send a remote assistance request. However you can send an invitiation file to the contact and they can open it
Example of RAInvitiation.msrcincident
code:
<?xml version="1.0" encoding="Unicode" ?>
<UPLOADINFO TYPE="Escalated">
<UPLOADDATA USERNAME="PCUSERNAME" RCTICKET="65538,1,IP ADDRESS:3389;ComputerName:3389,*,sewwXqwhTPaaSAsaIe60751ztt1YCK+Ccoa3cdHpMAA=,*,*,shbficiuYjk9cuvQVxFKhXPgtNk=" RCTICKETENCRYPTED="0" DtStart="1157306553" DtLength="INVITIATION TIMEOUT IN MINUTES" PassStub="PASSWORD (ENCRYPTED)" L="0" />
</UPLOADINFO>
Alternately you can Send the keycombination of Alt+A and then R to the window. That should open the Actions menu and then send a Request for Assistance.
More info can be found here :
http://support.microsoft.com/kb/300692/
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