SED Substitution

Hi ,
I am stuck up in the below scenario:-
I need to read a file name (eg A.txt) name frm another file (eg B.txt) and then I need to search for a particular expression in A.txt and substitute it with another expression.
How can I use SED inside SHELL Scripting and command prompt as well to execute the above problem.

The below is the script which I was trying to execute but I am not getting the desired O/P

++++++++++++++++++++++++++++++++++++++++++++++++
#!/bin/sh
FILE="$1"
echo ############################
echo $FILE
echo ############################

exec 3<&0
exec 0<$FILE
while read line
do
echo ############################
echo $line
echo ############################

FILE1="$line"
echo ############################
echo $FILE1
echo ############################

sed 's/feature\/frame\/work/vobs\/syscomp02\/comm\/work/' $FILE1

done
exec 0<&3
+++++++++++++++++++++++++++++++++++++++++++++++++++++
Where $1 is the input file which has the name of files to be edited.

Could someone please help?

Thanks in Advance,
SD.

If my understanding of your problem is correct, try the below one..

while read line
do
perl -ne 's/search/replace/; print;' $line
done<B.txt