In sheet: All,
In A6:B6 down are ClientID/Symbol data, eg:
AA MT
AA JPM
BB HIG
AA PCS
BB GE
BB GE
BB AIG
etc
(there may be duplicate clientID/symbols listed, eg BB - GE above)

In another sheet: T,
C1 contains the clientID, eg: BB

In B19 down are client BB's existing symbols eg:
HIG
TXT

What I need is for a sub to go to All, gather all the unique symbols
associated with the clientID in T's C1 (ie: BB), then check these with the
symbols already listed in T (in B19 down) and add any new symbols into T's
col B (append below) in red/bold font

For the sample data above, I would expect to see GE & AIG written into T's
B21:B22 (the order for the 2 symbols is immaterial). Thanks