Workday function

I need help with the Workday function in what seems like a simple problem but I can't think of a solution.

I have a workday function that uses a trade date and calculates T+3days effectively which must be 3 working days (hence the workday function). I also need it to exclude public holidays... easy enough.
Where I am having the trouble is that I use the function in multiple places for various trades that could be from 1 of 8 jurisdictions which obviously all have their own public holidays. I therefore have 8 columns in excel with the lists of the public holidays. What I want to do is ensure that my workday function 'extracts' the list of public holidays from the correct column. So if the trade happens in the US it looks up to column 2 which is the US and pulls the list of public holidays into the workday function. I just don't know how to do this cleanly. Embedded ifs don't work as it exceeds the number and I would prefer a cleaner solution. I would think I need some sort of array or something which really isn't my strong suite, please help.

Thanks