Bringing custom data into Google analytics

<script type="text/javascript">
$(document).ready(function(){
var fullstring = getParameterByName("redirect");
var subdomainarray = fullstring.split("/");
var sub_domain_url = subdomainarray[2];
var img_hit = '<iframe src="http://4520586.fls.doubleclick.net/activityi;src=4520586;type=Freet0;cat=FreeT0;qty=1;u1=['+sub_domain_url+'];cost=[Revenue];ord=[OrderID]?" width="1" height="1" frameborder="0" style="display:none"></iframe>';
$("#doubleclick_img_pixel").append(img_hit);
});
</script>
<div id="doubleclick_img_pixel"></div>

Select allOpen in new window

We are using DFA / DCM (Doubleclick for advertisers / Doubleclick campaign manager) as our adserver. We need to passback a unique ID for each conversion that we get.

We don't generate an order ID or transaction ID for each signup but we do generate a unique thank you page URL for each signup.

This is the thank you page where we would have the DFA conversion tag:
freshdesk.com/signup/thank-you

This is the unique thank you page URL that would be generated for each signup (This is just for one account):
http://freshdesk.com/signup/thank-you?redirect=http%3A%2F%2Ftestcompanyname1.freshdesk.com%2Fsignup_complete%2FndPAXFOfs7TEYnbE5WsC&account=testcompanyname1

The javascript code snippet that I posted would work on this URL.

So, in DFA we created a custom variable and pushed this data in. Atleast that is what our webmaster told us.

So, how do we push this data into Google analytics (universal) as a custom variable / custom dimension.