Apache mongrel and IIS..hosting asp and rails on same server

Hello,   I am running ASP.NET on IIS and on the same server am running rails. I have started multiple instances of mongrel as service and apache does the load balancing. THE PROBLEM IS i want to run the ASP.NET website on IIS and at the same time run the rails website through apache mongrel combination(Suggest any better way if you have). Since I can only run one website at port 80. How am I to achieve this.? Also I want my primary server to be IIS, i.e if any routing is done it should be done from IIS to apache. Please help. Thank you.