sed - replacement file path with variable - Escaping / character

Hi,,
I have the line below in a file:

$!VarSet |LFDSFN1| = '"E:\APC\Trials\20140705_427_Prototype Trial\Data\T4_20140705_Trial_Cycle_Data_13_T_Norm.txt" "VERSION=100 FILEEXT=\"*.txt\" FILEDESC=\"General Text\" "+""+"TITLE{SEARCH=NONE  NAME=\"New Dataset\" LINE=1

I want to write a script to change it to:

$!VarSet |LFDSFN1| =  '"T4_20140705_Trial_Cycle_Data_13_T_Norm.txt" "VERSION=100  FILEEXT=\"*.txt\" FILEDESC=\"General Text\" "+""+"TITLE{SEARCH=NONE   NAME=\"New Dataset\" LINE=1 

i.e remove the section of the file path.
E:\APC\Trials\20140705_427_Prototype Trial\Data\

The file path and the file names are varibels defined by

DATA_FILE_NAME=$(awk -F'"' -v VAR="$FILE" 'NR==4 {print $2}' $FILE)

giving me : E:\APC\Trials\20140705_427_Prototype Trial\Data\T4_20140705_Trial_Cycle_Data_13_T_Norm.txt

DATA_FILE_NAME_NO_PWD=$(echo $DATA_FILE_NAME | awk -F'\' '{print $NF}')

giving me: T4_20140705_Trial_Cycle_Data_13_T_Norm.txt

I wanted to use SED to replace $DATA_FILE_NAME with the $DATA_FILE_NAME_NO_PWD, however I can't get it to work. I know its due to the / in the variable $DATA_FILE_NAME however i can't work out how to escape this character. I've tried as many ways as i can find, but still can't get it to work.

How do i get this to work, what have i missed?

sed -i "s|$DATA_FILE_NAME|$DATA_FILE_NAME_NO_PWD|" "$FILE"

Either replace the backslashes with something the shell/sed isn't going to try and interpret, or escape them with backslashes, e.g.

DATA_FILE_NAME=$(awk -F'"' '{print $2}' $FILE | sed 's|\\|\\\\|g')

Assuming that I understand correctly what you're trying to do (i.e., delete the directory portion of the pathname in the first double quoted string on the 4th line of a file), this seems to be an easy way to do it:

sed  -i '4s/"[^"]*\\/"/' "$FILE"

This will not, however, work correctly if there is no directory given in that first double quoted string.