I have a macro that runs a pop-up calendar and applies the date selected
from within the calendar to the currently selected cell.

As default I have to run this manually via tools macromacrosrun.

My question is, how do I force this so that as soon as the user clicks on
the cell that particular macro (OpenCalendar) is run and the calendar is
opened for populating the cell that has just been clicked.

If possible i'd also like to limit any user entry for certain cells other
than that populated by the calendar macro.

Thanks in advance