Substring Function

Shell Programming and Scripting
1

Just so you know guys, I am a SAP Person and I am very new to UNIX. I need a help on a one line code.

In one of our script we are referring to a variable ($PN) which has the value /interfaces/DA1/DEV291/outbound/INVOIC which is being used in ftp command. I am just looking for a command to have a another variable which will have the substring of $PN.

Our Current Code
PN=$1
FILE=`echo $PN awk -F / '{print \$NF}'`

echo quote rcmd call CSP105 "('$PN' '02')" >> /interfaces/DA1/DEV291/outbound/$FILE

Needs to be replaced as
echo quote rcmd call CSP105 "('$XX' '02')" >> /interfaces/DA1/DEV291/outbound/$FILE

Right now the $PN is holding the value of /interfaces/DA1/DEV291/outbound/ our new variable XX should have the value of /DA1/DEV291/outbound/

Thanks,
Sasikumar

2 
xx="/"${pn#/*/}