help please!

ok so heres my problem...

I have a bunch of columns that are being populated by VLOOKUP and also INDEX/MATCH combinations.. On my sheet I have a column for "owners" and there is a list of companies in that column.. I also have a list for "Clients" and then Companies are listed in that column.. Most of the time these two are one in the same.. for example the owner could be Microsoft and the Client could be Microsoft as well. But sometimes there is a uniqe client with an owner.. so microsoft could be the owner but then "Craigs PC Services" (I made that up) could be the Client. I want to know if there is someway (using a radio button or checkbox or something idk..) to put a dropdown for the client list as a default setting and then install a radio button or checkbox that you check if the owner and client are the same (kind of like when you order something online and it asks you if your billing address is the same as your shipping address, and you click the box and it auto populates your billing from your shipping... you get the point..) Anyway.. I hope someone can help... thanks