Programmable Device Simulator - Variable value sources

Hi All
I just had my revelation that Ignition has an in-built simulator and so excited to try it. I was wondering if there is a way to add a variable value source. So instead of having a ramp(0.0, 10.0, 100.0, true) as a static entry in my program (instructions) I would like to get the min and max value from the user through a client/ session, ramp(min, max, 100.0, true) ?

Is this possible? TIA

Cheers
Sam

Ive tried something like that before and didnt really find it, but i didnt bother to long with it.
Writing over the tag value into a other one of the functions just didnt realy do anything either.