It's possible with PHP
I need to know how your page is structured, though.
If you can get your item's ID from the page that you have that would be the best.
Otherwise you're going to have to go through each item page and put a different link on them.
Your contact page is going to have to be in PHP and what you have to do is alter the contact link on each item page.
So for example say your item is an apple your contact link would look like this:
Code:
<a href="contact.php?item=apple">Contact Us</a>
Now when you get to your contact.php code you have a hidden input field with that item. like this:
Code:
<input type="hidden" name="prevpage" value="<?php echo $_GET['item']; ?>" />
I need to see how your page is structured first and then I can do it fairly easily