Custom build variables ignored when used in configuration build settings. Limitation or bug?

Hi,

I am currently using TeamCity 5.0.3 on a server named VMMOBUILD02.

I have used an environment variable (PARAM1) into my build configuration settings, namely, the VCS checkout directory which is set to:

P:\WS\TeamCity\%env.PARAM1%

In order for my agent to be compatible for the build, I had to define this environment variable, which I defined to "Hola".  So far, so good.

Then I try to access the server to trigger a custom build (specifying a custom PARAM1 environment variable) using this HTTP command:

http://VMMOBUILD02/httpAuth/action.html?add2Queue=bt2&env.name=<PARAM1>&env.value=<Bob>

The build is triggered allright, but in the "Hola" directory, whereas I wanted it to be into "Bob"

Am I doing something wrong or is this a limitation or a bug?

Is there a workaround?

Thanks