Allowing user to select a cell but not edit it?

My situation:

I have an event handler that runs a procedure when a user double clicks a cell. This procedure modifies the contents of this cell and other cells. I want the user to be able to select the cell so they can double click it, but I don't want them to be able to single click it and modify it by hand (accidentally or not). Is there a way to lock/unlock the contents of the cell without locking the cell itself?