exmh (tcl? sh?) quoting question.

[Shaul Karl <shaulka@bezeqint.net>]

The following is an bad attempt to use exmh `Apply command to body' 
feature.
However I believe it boils down to a tcl or a sh quoting question.

What I am trying to do is to filter a message by applying a filter to 
its body.

Now this filter

    sed -n "s/Inst//p" $file > /tmp/apt-get-update

works. However this one

    sed -n "s/Inst\(.*\)(.*/\1/p" $file > /tmp/apt-get-update

gives the following error message:

    bin/sed: -e expression #1, char 10: Unterminated `s' command

But why? The line is perfectly legal when issued from the command 
prompt.

-- 

    Shaul Karl
    email: shaulka@bezeqint.com
           The above address is meant for spammers. All the others
           should replace .com with .net to get my real address.