I have a userform with a number of combo boxes. I would like to be
able to compare all the values, which the user has selected, with a
table on a spreadsheet. The top axis of the table has all the combobox
names on it, and the vertical axis is just numbers from 1 to N. Each
cell in a row of the table may contain a possible value of the combo
box, whose name is at the top of its column. The cell may also be
blank; this represents a don't-care. Each row then represents a
combination of values which are forbidden on the form.

EG. The table might look like this:

¦Combo1Name ¦Combo2Name ¦Combo3Name ¦Combo4Name
-------------------------------------------------------------------------------------------------------------------------------------
1 ¦Value1 ¦ ¦ValueTuesday ¦ValueMay
2 ¦Value1 ¦Valueb ¦ ¦
3 ¦Value3 ¦ ¦ ¦ValueJuly

Meaning that the values, as represented in rows 1, 2 and 3, cannot be
chosen in combination. If they are, I plan to make a warning appear.
I think I should check this on the change event of the combo boxes,
but I'm just not sure how to go about checking the combinations of
values against the table.
I'd be most grateful for any ideas.