controlling a form drop down based on selection of another drop down

I've got a form that has a selection of drop downs - I'd like one of the drop down later on in the form to be controlled by what a user selects in the first drop down - e.g. the first drop down has A, B, C, D, E to select from - if they select A I'd like the later drop down to show certain list, if they select B I'd like it to show a different list and so on. Is this possible? Many, many thanks as ever!

If you have a dynamic range in the workbook, whose size relates to the value of the first combobox
e.g. on Sheet1
column A|column B
A Ai
A Aii
A Aiii
B Bi
B Bii
C Ci
C Cii
C Ciii
etc whatever...

and C1 is linked to CombBox1.ControlSource
with a named range "MyRange"
=OFFSET(Sheet1!$B$1,MATCH(Sheet1!$C$1,Sheet1!$A:$A,0)-1,0,COUNTIF(Sheet1!$A:$A,Sheet1!$C$1),1)

Then put something like this in the the _enter event of ComboBox2 or _exit event of ComboBox1

ComboBox2.Clear
if thisworkbook.sheets("Sheet1").range("C1").value<>empty then
for each c in thisworkbook.sheets("Sheet1").range("MyRange")
ComboBox2.additem (c.value)
next


You'll probably need to tweak it a little...
Col