Auto Calculate SUM formula in Table

I have a blank table (not form) with headers which gets filled in, row by
row, as transactions occur. I'm trying to SUM one of the columns (simple SUM
function). I'm trying { SUM(ABOVE) } which works if the table is already
filled out. But if it's blank and gets filled in, the SUM does not calculate
or update automatically. I'd like it to keep a running tally. I've also
tried { SUM(F2:F17) } excel-like code for the cells of the table I'm trying
to SUM but I get the same results; it only adds information already there.
I'd like it to function like excel does, auto updating as the numbers get
entered. Are there field codes or another way to write this to get it to
happen in a Word03 table?
Thanks in advance,
Dax
--
I would give my left hand to be ambidextrous!