need to write a macro to count a column without dups or blanks.

what i currently do is

Insert | Name | Define from the menu to give the range a name. I called it Names.
the rang i choose is the amount of data i have. then I enter this formula:
=SUM(1/COUNTIF(Names,Names)). and i get the amount.

this is all good and it works. but now i have someone taking over my position and the are very computer iliterate. i need to make one that i can select the whole range(the whole column) then minuses dupicates (as the one above does) and minuses the blanks.

please help.

Thank you