linking progress variable to other variables

Hi,

Im trying to create a model for a project, my current model is adiabatic but im adding heat loss through enthalpy.

What i want comsol to do at this stage, while i have the following:

a progres variable that goes from 0 to 1 to 0 again, dependant on time
a number of variables dependant on progres variable from 0 to 1 ( not the same values for PV as in the time dependant one)

So how can i link these in a correct way, that when the progress variable gets a certain value at a certain time, the other variables get assigned a value corresponding to the nearest progress variable?

regards