This is Karthik and i have 10+ Years of experience in IT industry and well-versed with Excel. If I Understand your requirement correctly, You just want one cell with a dowpdown value of "IE", "FF" and "Disable". Whenever you click on column A or B (or Both), your selectionchange macro has to use the selected browser value from dropdown and open the url using that browser. Suppose if the "Disabled" option is selected from dropdown, Nothing should happen (Browser shouldn't open).
I have modified the macro to achieve the above and it is ready. I can send it toy you rightaway. Waiting for your response. Thank You.