SilkTest: how to define expression for dynamic drop down list

Question

How do I define an expression (or any other alternative method) when I want to select a value from a dynamic drop down list?

ex: drop down list has these values: Plan A (X) Plan B (Y) Plan C (Z) where, X, Y and Z are all random numbers.

Is there a way where I can define my selection to select the text up to "Plan #" and ignore the "(X)"?

Thanks