perl -pi -e shell_escape('s#\Q(.*)\$/\',\$lines,\$matches))10.(.*)\$/
+\',\$lines,\$matches))(.*)\$/\',\$lines,\$matches))# #gi')  result.tx
+t > result1.txt
[download]

\' doesn't work in single-quoted literals in bourne shell.

$ echo 'foo\'bar'
>                      <- waits for closing '
[download]

Fixes:

$ echo foo\'bar
foo'bar
$ echo "foo'bar"
foo'bar
$ echo 'foo'\''bar'
foo'bar
$ echo 'foo'"'"'bar'
foo'bar
[download]

From the bash manual:

A single quote may not occur between single quotes, even when preceded by a backslash.

Hence - my previous suggestion is invalid - there is no "escaping" inside a single-quote.

Here is a shell trick to try:

 '"'"'
[download]

Replace all perl-directed single quotes with that, and it should work.

Extremely ugly, though. Here is how it works:
It starts in single quotes, and which you want a single quote you come out, go into double quotation to quote a single quote, then come out of double quotation, to go back into single quotes again.

Using this trick, your command passes the shell's syntax:

 perl -pi -e 's#\Q(.*)\$/'"'"',\$lines,\$matches))10.(.*)\$/'"'"',\$li
+nes,\$matches))(.*)\$/'"'"',\$lines,\$matches))# #gi' result.txt > re
+sult1.txt

-- Output (from perl - bash is happy!!!) --
Can't open result.txt: No such file or directory.
[download]

Update: I just noticed that my shell trick is identical to ikegami's (++) last example.

     Have you been high today? I see the nuns are gay! My brother yelled to me...I love you inside Ed - Benny Lava, by Buffalax

Hey NetWallah Thanks for the help...The error is gone...But cant see any result in result1.txt .. So , may be some match is not done or so... the string in file to be removed is

(.*)$/',$lines,$matches)        10.(.*)$/',$lines,$matches)     (.*)$/
+',$lines,$matches)
[download]

There are tabs in between.. Thanks