Q:

Restrict MS Word Content Control Functionality

I have a MS Word document and that document has multiple content control. When user copies entire data from one content control to another sometimes it copies content control itself with data and when user pastes data it creates nested content control.
Question:
Somehow I need to restrict Word document so that user can only modify data and additional content control cannot be created. How can I achieve this.

A:

I don't think there is a setting in Word that can control this; there isn't a content control property that does.
So I think you're looking at a VSTO Word Add-In, or possibly a VBA macro.
With VSTO, have a look at the content control event model. Maybe Document.ContentControlAfterAdd fires on paste?  Googling .. apparently it does, subject to an issue 

when the content controls are in table cells, and the user chooses to
  insert a column: the BeforeDelete is fired for all the content
  controls in the table, but AfterAdd is not raised when the column
  insertion completes.

Check out the other content control related events as well - start by seeing which fire when the user does what you are concerned about, and of course, what other situations they fire in (which your code will have to ignore).
Otherwise, you could try a more generic way of capturing paste.  There is:

this thread
and the keyboard hook approach

