Shane Devenshire wrote...
....
Additionally, if Ref : only appears once you could use

=LEFT(A1,FIND(":",A1)-6)

No, if : appears just once, your formula would work. If there were
other, preceding colons, your formula would fubar.

If the OP really does want to remove this stuff, and if there were
only just one instance of 'Ref : #...' in each cell, wouldn't it have
been faster for the OP to replace

Ref : *

with nothing using Edit Replace?