How to change a parameter during a simulation (Pro-E Creo)

Hey guys,

i got a problem. I try to change a parameter with relationships of one of my constructions from my assembly and all that DURING a mechanism-analysis.

Until now i could change the parameter i wanted but only in relation with a fixed value if i edit a fixed size manual, but during the mechanism-analysis the programm don´t registrate a change in parameters so the one i want to have changed rest how it is...

Does anyone know a solution or how the time-parameter of an analysis as a value in the relationship-window is called so that i can make my parameter depending on that time-value so that my parameter changes on a fixed time...?

Please it would be nice if you can help me...i´m trying to find a solution for a few hours now...

Philipp