Setting dependency to a Test Case.

What you'll need to do is create a Groovy Script Test Step that runs the dependent Test Case.

I've created an example:

import com.eviware.soapui.support.types.StringToObjectMap

def externalTestCase = testRunner.testCase.testSuite.project.getTestSuiteByName("Test account creation").getTestCaseByName("accountcreation TestCase")

return externalTestCase.run(new StringToObjectMap(), false))

Where the new StringToObjectMap() can be replaces with a map of properties for the dependent Test Case and the second argument (true/false) says wheter to run the external Test Case asynchronously.