What does this mean, "the values in the data Validation which will activate a macro"
By "values in the data Validation" do you mean the values in the list of options from the user to choose?
When do you want that macro to be run, when the userform changes the Validation list or when the user makes a choice in the cell?
Where is the cell getting its current validation list? From a range (if so what range) or from an explicit list?