Using Hooks to Dynamically populate single line text

Hi all.

I have a question that needs answering. I've looked through the forums and documentation but haven't found exactly what it is I'm looking for.

I'm trying to populate a "subject" field with the wordpress page title. In this case it's an address.

I've tried several things including
[gravityform id=3 name=Contact title=true description=true field_values='subject=$page_title']
where $page_title is what I want to be populating the subject line in the contact form.

So my question is, what do I need to replace $page_title with to get the actual title of the specific page a user is on? Ideally I don't want to have to create hundreds of contact forms for every specific page.

Is this even possible?

Thanks!

Thank you!

I guess my question is now this: what would be my return value? $page_title?