Add items together after a sort

[M.Siler]

I've added the AutoFilter on a few columns and I would like a column to add
up. I know about subtotal(9,rage) but when I say add, not as in math, as
the column has text in it. It is a column of states (FL, TX, NY, etc.) When
I filter on something else I'd like to see at the bottom something that
looks like this if I had three rows after the filter. Lets say the states in
those rows were FL, TX & NY

What do I do so I get
~FL~TX~NY~

then if I change the filter and I have FL, SC, NV, TX, WA I'd get

~FL~SC~NV~TX~WA~

I'm using Excel 2007

Thanks,
Mark