HSPICe and ModelSim on the Same System

I already had the HSPICE and ModelSim on two different systems but now I want to have both of them on the same system but since both their license files name in the environment variable is the same (i.e. lm_license_file) this name of variable only can be set to one value and then I installed them on different drives but it didn't work again. Does anybody know how to have both on the same system?

Analog Software, Digital Software