piping & executing external commands (STDIN)

[Jorg Ziefle]

I want to pipe a message from within Mutt to a Perl program, which not
only processes it, but as well reads some user input from STDIN.  As far
as I know, the <pipe-message> command ('|') only allows to _write_ the
message to STDOUT, but then returns immediately (as its name suggests).

So, is there a possibilty to achieve printing to a message to an
external program which is then executed _before_ returning to Mutt?

Thanks,

J�rg