Many thanks to Michael Heiming for his prompt reply (as follows)
'bkfiles="directory1 directory2 \"My Documents\" directory4"'
directory1 directory2 "My Documents" directory4
Although this works when I plug this into smbclient as follows -
smbclient //$user/c$ password -U username -Tc - $bkfiles | gzip > $opfile
smbclient correctly backs up directory1, directory2 and directory4 but also
attempts to back up the two directories "My and Documents".
If I type the following -
smbclient //$user/c$ password -U username -Tc - directory1 directory2 "My
Documents" directory4 | gzip > $opfile
all four directories (including My Documents) is backed up. Can anyone help.