I'm trying to disable the click of the comma button on a particular
worksheet in my excel workbook. Using the application.onkey feature I
have been able to disable this when a user single clicks on a
particular cell and tries to click the comma button.

The problem is, if a user double-clicks on a particular cell, or types
an accepted character in a cell, then the block on the comma no longer
applies and the user can enter the invalid character.

Any ideas how to get around this problem?

Thanks