Hi,

you can do it without any function call by using the Pattern-matching operators (which are faster).

for instance:
me@host> BackupLocation='abc/dfg'
me@host> SubDir=${BackupLocation##*/}
me@host> echo ${SubDir}
dfg
me@host> BackupLocation=${BackupLocation}/${SubDir}$(date +%w)
me@host> echo ${BackupLocation}
abc/dfg/dfg5

(see 'KornShell/Pattern-matching Operators',
[Chapter 4] 4.3 String Operators)

Hope it helps,
Christophe