Setting environment variable to run different versions of Quartus

Hi,

I have installed different versions of Quartus on my Windows PC. { Versions 13.1, 16.0 and 16.1} . I want to be able to run all versions on my PC { net necessarily at the same time } on my PC. Now my question is how to set the Quartus environment variables on my PC.

My current environment variable is set as follow and I do not want to change every time I want to bring up different versions of Quartus:

QUARTUS_ROOTDIR = C:\intelfpga\16.0\quartus

Path = C:\intelFPGA\16.0\modelsim_ae\win32aloem

QSYS_ROOTDIR = C:\intelFPGA\16.0\quartus\sopc_builder\bin

SOPC_KIT_NIOS2 = C:\intelFPGA\16.0\nios2eds

Can I add the environment variables to different versions at the same line ? For example can i change to something like this:

QUARTUS_ROOTDIR = C:\intelfpga\16.0\quartus ; C:\intelfpga\16.1\quartus ; C:\ialtera\13.1\quartus

and do the same to the other Quartus related environment variables?

Thanks