Yes, a little script file is probably the easiest way.
Name your scud scudname, or whatever you like. Now open up a text editor like Notepad and copy and paste the following:-
; this script gets the scud to launch
scudname action ["scud launch"]
~10
scudname action ["scud start"]
exit
Save the file: call it scud.sqs (or whatever you like). Make sure it is not called scud.sqs.txt. Put the file in the mission directory with the mission.sqm
Now go back to the mission editor andcreate a trigger, activated as you will. In the on activation field write
[] exex "scud.sqs"
That's all there is to it.
~10 tells the script to wait 10 seconds, watch the thing in action and change it if its too long or too short.