I think you can change a bit the scenario of the anlytics referral tracking to pass parameters to your app during installation if you need...
You have to declare a custom receiver for com.android.vending.INSTALL_REFERRER in the custom receiver parse the url from the market.
If you want the analytics to work as well, is better if you extend the com.google.android.apps.analytics.AnalyticsReceiver and call the super.onReceive
There are two parameters that are optional in the referral the campaign term and the campaign content so I will put there the information you want to pass
I worked a bit on this and I wrote a post where I explain even how to test it : http://www.dev-articles.com/article/Analytics-referral-tracking-for-Android-447001