How to restrict copy paste in drop down list?

I have one more issue...In my data sheet, I have 3 columns (Priority, Modules, Ticket Types) with 3 different drop down lists.
I want to apply the above validation code for all three columns...The problem is that it's allowing user to copy any cell from a drop down and paste in the other drop down column..so the whole drop down list gets changed after pasting....how can we avoid this?

In short, I want the user to be able to copy n paste cell within a drop down column only and can not be able to paste data copied from one drop down column to other different drop down column. Please help me in writing validation codes for all 3 columns.

Hi,

Can anyone help me to restrict the user paste/paste special from drop down list.

For convenience, I am attaching herewith the excel. Need to restrict user in A,D,E,F and I (Highlighted in purple color)

Kindly use the excel "Abhi data"

Thanks in Advance

Abhishek