mime QP and B headers in body

[Dan Jacobson <jidanni@dman.ddts.net>]

>I make a daily spam report and send it to myself in the body of a mail message:

> Subject: =?BIG5?B?ttmhS...
> Subject:=?big5?Q?=A7A=B...
> Subject: Want a BIG Pen...
> Subject: =?GB2312?B?1tC...
> Subject: =?ISO-8859-1?B...
the reply posted didn't work because my perl doesn't have concat() or
something.  Here's another approach

my $bdy='----=_NextPart_'.rand();
print '
This is a multi-part message in MIME format.

'.$bdy.'
Content-Type: multipart/alternative;
	boundary="'.$bdy.'"'

s/=\?([-a-z0-9]*)\?([BQ])\?([^?]*)\?=/$bdy . '\
Content-Type: text\/plain;\
	charset="'.$1.'"\
Content-Transfer-Encoding: '.if($2=='Q'){'"quoted-printable"'}elif\
    ($2=='B'){'"base64"'}.'\
'.$3.'\
\
    '.$bdy/e;

Unfortunately my perl is bad so someone help me maybe.
The idea is to simple turn the =? seperator sequence into the larger
style seperator sequence.