When calling external processes like MSBuild cruise control sets environment variables. One of values is CCNetLabel. it holds the value of the current projects label. I want to use the same values in ccnet config itself but when I try ccnet config has a problem. I get the following error:

[CCNet Server:ERROR] INTERNAL ERROR: Reference to unknown symbol CCNetLabel
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ThoughtWorks.CruiseControl.Core.Config.Preprocessor.EvaluationException: Reference to unknown symbol CCNetLabel
at ThoughtWorks.CruiseControl.Core.Config.Preprocessor.ConfigPreprocessorEnvironment._GetConstantDef(String name)
at ThoughtWorks.CruiseControl.Core.Config.Preprocessor.ConfigPreprocessorEnvironment.eval_text_constant(String name)

.....

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I actually want to append the CCNetLabel to another variable so I need to access the property in ccnet.config.

is there a different way to reference these variables?