But if you just gotta have executable code in the search pattern, try something like:

c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my $s = qq{xxx\x0cyy\x0czzz};
 dd $s;
 ;;
 $s =~ s{ \Q@{[ chr 12 ]}\E }{}xmsg;
 dd $s;
"
"xxx\fyy\fzzz"

"xxxyyzzz"
[download]

(But on second thought, follow the advice given you here and here by wiser monks than I :)