With this script you can use !call USERNAME and the bot will send a PM telling USERNAME that you want them. This will also tell you if USERNAME is not in the room.
<command type="script">
<in>!call %PARAM%</in>
<out type="push" extdata="ALLOWPM">2</out>
<out type="push" extdata="THEUSERNAME">%NAME%</out>
<out>/hidecmd /stats %PARAM%</out>
</command>
<command mode="thread" type="script" condition="==" lvalue="%USERVAR[ALLOWPM]%" rvalue="2">
<out type="push" extdata="%PARAM%"><operator type="strrep" nvalue="%PARAM%" lvalue="*" rvalue="∗"/></out>
<out type="push" extdata="%PARAM%"><operator type="strrep" nvalue="%PARAM%" lvalue="$" rvalue="§"/></out>
<in condition="5" lvalue="%NAME%" rvalue="_BOT_SELF_TRIGGER_">Username: %PARAM%</in>
<out type="pm" extdata="%PARAM%">$THEUSERNAME$ is looking for you in Omega's Music Palace_176283181A2A</out>
<out>/hidecmd /privnotice $THEUSERNAME$ #c6#Message to %PARAM% #c6#has been sent</out>
<out type="pop" extdata="ALLOWPM"/>
</command>
<command type="script" condition="1" lvalue="%USERVAR[ALLOWPM]%" rvalue="2">
<in>Unknown User</in>
<out>/hidecmd /privnotice $THEUSERNAME$ #c6#We are sorry, but the person you are trying to reach is not here.</out>
<out type="pop" extdata="ALLOWPM"/>
</command>