V5 Getting environment variables passed to custom command--Windows

[Andrew Van Order]

I am using Tivoli's postemsg command to open TEC events for a SIM event. The following parameters passed work fine:

-S server -r WARNING -m "Test" EVENT EVENT

If I try to pass an environment variable it won't run:

-S server -r WARNING -m "%USERNAME%" EVENT EVENT

postemsg passes environment variables fine at a command prompt so what gives? I've confirmed all variables I need are passed in the environment by first testing the custom command by running set > c:\env.txt. I did not need to specify any variables in the custom command config at all.

Thanks--Drew