sieve_extprograms - run any individual script?

[Hajo Locke]

Hello,

i use sieve extension sieve_extprograms to send incoming mail to some 
script.
For security reasons it is needed that script-paths etc. are registered 
in dovecot.conf
This is my current dovecot.conf
plugin {
  sieve = ~/.dovecot.sieve
  sieve_plugins = sieve_extprograms
  sieve_extensions = +vnd.dovecot.pipe +vnd.dovecot.filter 
+vnd.dovecot.execute
  sieve_pipe_bin_dir = /usr/local/bin/
  sieve_filter_bin_dir = /usr/local/bin/
}

.dovecot.sieve example:

if address "to" "t...@example.com"
{
        filter "myfilter";
}

This is all working without problems.

Is there a possibility to allow users the execution of individual 
scripts in own homepath? Some people need to pipe mails to scripts for 
immediately processing (some ticketsystems need this).
Is there a way to make this possible with sieve?

Thanks,
Hajo