Counting Names In Multiple Columns

Hello,
I've been using these forums for most of my questions,
however I've not seen this one posted before so..

I'm currently working on a client list where each
client has a dedicated row with all of their information.

In column A I have the clients Last name,
In column B I have the clients First name.
In column U I have the name of the person
who referred the client to me: (First name Last name)

What I need is to have column V show me how
many clients this client has referred to me by counting
how many times their name shows up in column U.

I'd like it to be able to update and be linked to the column
rather than having to enter a new formula every time I enter
a new client.

If every entry in U as also listed in A,B then the formula
Put this in somewhere in row 1 and fill down

=COUNTIF(U:U,$B1 & " " & $A1)

It should return the number of times that the person has refered another. You may need to tweak the space in the formula to match your formatting of col U.

Thank you for the quick reply,
how would I implement this into
the whole column for column V.

Also what space would I need to tweak?
The format for column U is First name
Last name (John Doe)

I apologize for my newbie approach and
questioning.

Also I'm using Excel 2007 if that helps.