How to track PPC campaigns that are not Google

How can I automatically add leads to a campaign if the referrer is one of my PPC campaigns? I know how to track it by using the hidden fields on a landing page specific to the campaign name, but as we know, visitors, don't always convert on the landing page you send them to.

I want to attribute all lead forms that are completed by a visitor with the PPC Campaign as a referrer from any page on our website.

I don't want to have to create a bunch of different PPC forms with multiple landing pages per PPC campaign. There doesn't seem to be a way to do a field update to add someone to a campaign or campaigns response field I created to capture my Zoho CRM email campaigns to capture my PPC Campaigns that are not Google PPC.

How can we replicate the Google AdWords PPC functionality to track any form a PPC campaign visitor completes?

The vendor does provide tracking code to show the conversion in their portal, but I don't know what data it could possibly push to Zoho.

Thanks,

Shannon