Ok, so I may have spoken to soon. For those of you who maybe haven't figured this out, you can use the "dynamic text" tool when you enter the destination url. This comes up as a little link on the right when you put your cursor in the box when creating a text ad. I made this work by using the parameter {keyword} in my query string.
For Google Cross-Channel, it would look something like this:
www.mywebsitesurl.com/landingpage.html?gad=googleslongidentificationstring&gkw={keyword}
I have some of my own tracking strings that I add on in case Google does not properly register the {keyword} string.
