Running TestPlan with different environment URLs

Hi All,

We are using SilkTest Classic16.5. 

We have two different test plans for our test cases.  If we run TestPlanA, we like to invoke one environment URL with a set of user and password.  If we run TestPlanB, we like to invoke another different environment URL with another set of user and password.  Can this be done within SilkTest?

Thank you for any input!