Clear Target before Import

rookieanaplaner

I have a users list wherein the users have read or write access to different companies. I have also created a security dashboard with an import action wherein administrators can give or takeaway access to certain companies for certain users. The problem I am facing is that in spite having the correct import action the new company access data doesn't overwrite the new one. Hence I am trying to create a new action that would wipe out the existing access data in the users list before importing the new data. For this new action I am trying to import a blank module wherein there is nothing in the company read and write columns but somehow anaplan doesn't seem to recognise blanks while importing. As an example

User A currently has write access to Company A,B,C,D and read access to Company E,F,G,H

Now I go to my security dashboard and make some changes after which User A has write access to Company E,G,H and read access to Company A,C,D.

Before running the import action to import these changes to the users list, I want an action that would clear the company read and write columns in the users list. Is there any way I can do that?