Issues on aseemblies parameters

Goodmorning everyone,

I have created a set of 4 parameters and I created a design talbe with all the sets of values of those parameters. Now I want to create 4 OFFSET RELATIONS between planes, by setting this 4 parameters to the lenghts.

I'm not able to understand how to link them. I also tried to create the design table choosing directly the lenght values of the offsets pre-created, but i cannot find the relations in the parameters that i can choose while creating a table, also by re-naming the offstes. 

I hope I was clear about my issues. Thank you very much! Let me know.