display drop down list in a vba gui

[joeloyzaga 0]

I have an .xls  that i use for automation that I have rather badly created a vba input gui. But that was a few years ago and now I need to enhance it to include a list for selection of test cases to run.; I have another spreadsheet that has all my testcasesand each worksheet has the test case name as its worksheet name. So what i would like is while my vba gui is displayed, I would like to create an autoit gui to display those testcase names in a drop down list that are there to be selected. either single selection or multiple - can anyone tell me how to do this? I am attaching the spreadsheet with the test case names. 

PWCOnline.xls