Variables in the SPEC section of Cadence Explorer

Hello everyone,

I am using Virtuoso IC 6.1.8. 

In explorer in the outputs setup tab, can we include a pre-defined expr name in the SPEC column. For example I have my VIH_spec as the name of the expr and in the details the equation calculating VIH_spec as (0.7 * VAR("Vsupply")).

I cannot seem to include the value of VIH_spec calculated above as the spec for another expr.