Require Double Left Click to Enter Data Into Cell

Hi...I've wrestled with the title of this thread. What I'd like to do is to require the User to double left click on a cell in a given range in order to enter data. If the user TYPES in that cell, they would get a message.

In the attached, if the User were to double left click on a cell in Column B, it'll bring up a Calendar from which the User can select a date. The date will then populate the active cell.

The issue I have is that the user CAN type anything into the active cell. I'd like to prevent this. So, if the User sends ANY keystrokes other than "Left Double Click" they'd get a message such as "Please Double Click To Bring Up Calendar".

I've been at this for some time now and haven't figured out a workable solution.

Sorry, the file seems to be too large to upload in native state.