What is your definition of "won't work" here? 
#!/usr/bin/perl -l

use strict;

my $find="find=1";
my $repl="repl:2";

for my $trial (qw/find=1 Find=1 FIND=1 fInD=1/) {
    $_ = "here is >$trial< data";
    s/\b($find)\b/ uc($repl) | ( $1 ^ uc($1) ) /eig;
    print
}

[download]
For me, that produces: 
here is >repl:2< data
here is >Repl:2< data
here is >REPL:2< data
here is >rEpL:2< data

[download]
Do you see something wrong with that? I'll grant that many accented characters won't work properly, in the sense that you'll get an incorrect character as the result, but actually, there are a fair number of them where the case distinction is a matter of a single bit being on or off (just like in the ASCII letters), and I'd expect those to work. (But I don't have time to test that just now -- and I'm sure not going to argue about EBCDIC...)

In reply to Re^2: Respect case in substitution by graff
in thread Respect case in substitution by b4swine

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