Count a column without duplicates - VBA Only

Hi Guys,

I've got Column (Pretend it's A) and I need to count the unique values. An example being:

Col A
1
2
3
4
4
3
2
1

Should return a count of 4.

Without using the COUNTIF Excel Macro is there an easier way of doing this other than:

-Copying the Column
-Pasting to new i.e. Column B
-Remove duplicates
-Count Column B
- Delete Column B
-Return count

Thanks,