VBA validation allow users to only copy to a specified range

Hello,

I'm setting up a valuation model where each statement line item has a number of potential drivers for projection purpose. for example, revenue has "% of Growth from Prev. Year", "Scenario driven", "Volume Change" in the validation list. I need to set things up so that the validation rule only applies to say Range("J12: G20") as only these are related to revenue (COGS would have a different input range, for example). When a user select an item from the validation list and if he/she wants to copy it to the other input cells (so he/she doesn't have to click on the cell and pick a value twenty times), I need to add some codes to limit the copy paste only to range J12:G20 so that the user doesn't incidentally copy this to other statement line input ranges. How can I do this?

just to clarify, this is different from not allowing pasting from another cell without drop-down in it. this is ALLOWING copy/paste but only to specified ranges or ranges with exactly the same drop-down values. I think this would be a change event after copy before paste (go check the cell selected for pasting, if it is outside of J12:G20, throw an error message and terminate the paste)

is this doable?

thanks so much