How to change recipient of a VACATION autoresponder mail to one in sender's mail header section [Reply-to] purely in Sieve Language?

Question

I need to set an autoresponder that will send a message like "We got You mail! We will get back to you ASAP". The problem is that the sender of customer email is not customer itself (i.e. [email protected]), but some global mail (i.e. [email protected]) that contains customer private mail in the header section [Reply-to].

This is a hosted server with installed RoundCube. I can only use Sieve filters to create an autoresponder.

rule:[Autoresponder]
if allof (
header :contains "from" "@marketplace.pl", 

{
    vacation text:
    We got You mail! We will get back to you ASAP!
.
;
}

I need to read the value of the header [Reply-To] section, set the recipient of autoresponder mail to that value and send a VACATION message. Only in Sieve language.