Hi,
The "from" is the sender of the email, not the receiver.
What you want to change is the "to".
The contact request is actually sent to the "From Address" that you configured in the HikaShop configuration, in the "email" section.
If you don't want to change that setting but still want to change the email address receiving the contact requests, you would have to edit the email via the menu System>Emails, and add such code at the beginning of the HTML or preload:
<?php $mail->dst_email = array('XXX'); ?>
where XXX is the email address you want to receive the email.