I wish I could help you, but I'm rusty, now... I think Icarus' conditionals are limited in functionality, if I remember correctly. But still, there should be some way to check for either a flag or a value...
In the IF event editor,in the third row there's a dropdown list and a 'Get' button which will write $get(FLOAT,"SET_PARM1")for you. I've sent you a PM with a script example.