UpdateText() not working correctly

I'm trying to run the following SQL against my column, Testtbl.Task

I want to replace where the ampersand sign got HTML encoded to
"&", and I want to strip it down to only the ampersand sign and delete the "amp" and the ";".

It executes, but I still have the HTML encoding for the ampersand sign.


USE WI
GO
EXEC sp_dboption 'WI', 'select into/bulkcopy', 'true'
GO
DECLARE @ptrval binary(16)
SELECT @ptrval = TEXTPTR(Task)
FROM Testtbl
WHERE Task like '%amp;%'
UPDATETEXT Testtbl.Task @ptrval 88 0 ''
--Tried this to @ptrval 0 0 '', @prtrval 1 0 '', etc
GO
EXEC sp_dboption 'WI', 'select into/bulkcopy', 'false'
GO

Sorry...line should have been:

UPDATETEXT Testtbl.Task @ptrval 0 8

...since the start will be at the "amp;" (0), and for each character it's 2 bytes (8), and with saying nothing for the update text, it just deletes the "amp;"...at least that's what books online says, but I'm missing something.