How to Use Response.Redirect and Pass/Keep All Existing Querystring Parameters In The Redirect

I wanted to know if there is a way to redirect the user from one page to another, but keep all the existing querystring parameters in the original page request.

Example:  User is on the URL domain.com/folder/page.aspx?key1=1&key2=yes&key3=456534234-5445435 and some action needs to redirect the user to domain2.com/folder2/page2.aspx but also pass all the existing querystring variables as the number of querystring variables in page.aspx differs occasionally (e.g. not always three querystring variables).  So the final redirect would take the user to domain2.com/folder2/page2.aspx?key1=1&key2=yes&key3=456534234-5445435 in the example.