Send to finder

[paolo mazza]

How can I send a command "control+shift+3" to the finder?

A kind of:
on MouseUp
  send  "control+shift+3"  to program finder
end MouseUp
or 
on MouseUp
  send  "control+shift+3"  to program applescript
end MouseUp

I need this peace of script to open the program "Snapz Pro" from Rev and let
this program to record a Quicktime movie of the animation is running on the
window on top of my stack.
Any of you ever tryed to use Rev and "Snapz Pro" together?