I have a combobox which changes certain cells on a spreadsheet depending on
the CB selection and the content of several other cells. The problem I have
is that if one particular cell does not have a value entered, the data in
the code assumes a certain set of conditions. If data is then entered in the
cell, the other data is not corrected as it depends on CB LostFocus.

Is there a way to disable the CB but still leave it visible until certain
cells in the sheet are populated? I know about the Enabled property, but I'm
not sure how to detect the presence of data in particular cells except from
within a subroutine. I suspect I need to use the Worksheet SelectionChange,
but I only want the code to test conditions when particular cells are
changed.

Am I being thick, here?