How to get command line argument in Groovy

Hi,
Is it any correct way to get in Groovy command line argument which is used for testrunner run.
For instance, for testrunner we can pass Custom Args (at the end of command line)
testrunner.bat soapui-project.xml MyCustomArg
How we can get the MyCustomArg in Groovy?
Or is there any way to add property on project level in runtime from command line?

Thanks in advance.
Sergey.