using closures defined in a testSuite in a Groovyteststep

Hi,
I solved my Problem Like this:
I created a Propertyvalue in the Testsuite. It's a closure in a String.

add='{a,b-> a+b}'
testSuite.addProperty('add')
testSuite.setPropertyValue('add',add)

And it can be used in a Groovyteststep like this

sh = new GroovyShell()
closure = sh.evaluate(context.expand('${#TestSuite#add}'))
return closure('ha','lo')

But there has to be a better Solution. Can I use something like context.createStatement() in the free Version of SoapUI? and How?

hm... don't know if it helps but somewhere in the Forum rules I read something like I should write "HELP ME" to get replies faster. Hope I got this right. my English is not so good. I know, you allready noticed.