What I am try to do:
Populate a list for a combo box. The drop down is on a
front sheet (not a userform) and on pressing it I want it
to filter the data on another worksheet (to have unique
values) and populate the list with a column of the
filtered data. The user will then select a category from
the list, the value selected will be used to refilter the
data on the other sheet to display records for that
category only. This will then be copied to another sheet
which is used as source data for a chart. This is
displayed to the user, I would then like all data to
return to unfiltered state.

I am happy with my filtering/ copying code however I'm
stuck with the Combo/List code
I am using
Sub ComboBox1_DropButtonClick()
My difficulties a
1/ The code is run not only on pressing of the dropbutton
but also on selection of a value from the list. What can I
use to only run it once?
2/ I would like the list do be displayed mid sub so the
value selected can be used straight away (i.e. ShowAllData
then I can refilter for the category) Currently the list
is displayed after the End Sub. Is the only way to do this
by having an InputBox (if so how can I have a Combo Box
within a InputBox)???
3/ I want to use the Cells(x,y) notation rather than Range
("Data!C2:C1000") so that the the list doesn't contain a
lot of blank rows i.e.
Sheets("Front_End").ComboBox1.ListFillRange = Sheets
("Data").Range(Cells(2, 3), Cells(Rownumber, 3)) this
gives an Run-time error 1004 'Application or Object
Defined Error'[Rownumber has just counted the rows which
contain data from filtered list]. Or is there a better way
to do this?

Any help on any of the points would be greatly received.
Cheers
Laura