Is it possible to create a custom pre-defined test script type?

I'm developing a custom automation adapter for Quality Manager. Unfortunately, the custom test script type creator provides only text, boolean and integer fields for input parameters. But I need  4 textfields, 1 dropdown list, 1 text area and a button. I know that these elements can be implemented in a pre-defined test script type, like in the Rational Functional Tester type for example. That's why I'm asking, if it's possible to create a custom pre-defined test script type. Or maybe is there another way to create such a test script type with elements I need?

Sincerely, Roman Syrych