How can you accomplish that with a plan? I have found the plan to very useless, or at least I can' seem to find a pain's free way of using the plan to my advantage. I use a script.t file as my suite, we put a use statement for all the script.t's that are associated to that suite. and then the Main function is basically a list of the test cases in the suite, but doing this also gives the benefit of code logic in the main function, or writing functions used just for that suite.
(FYI, All of out test cases are contained in it's own script.t, meaning we have 3200 test cases, and there are 3200 script.t files for each test case, it's the only way i could find a trace route back to our Test Case Management System, all unique by a test case ID, and the script.t are named to the test case id.) I though you should know this information before commenting on my statement.