use strict;
use warnings;

#sourcedir, as it comes from <STDIN>, hence it has a newline
my $sourcedir   = 'C:\Documents and Settings\Administrator\Desktop\eit
+v9_lvttest' . "\n";
my $folder_path = 'C:\Documents and Settings\Administrator\Desktop\eit
+v9_lvttest';
my $file = "test";

#get rid of newline
chomp $sourcedir;

#escape backslashes and other possible regex-affecting meta-characters
my $sourcedir_regex = quotemeta($sourcedir);


if( $folder_path =~ s/$sourcedir_regex/Eitv9/ )
{
    print "\n$folder_path/$file";
}
[download]

This prints "Eitv9/test".