Asp.net Web Api as an Api Gateway

In my organization I have several asp.net web api projects.
I'm willing to develop an web api which will act like a gateway and have single entry point.

I tried handlers and filters but routing doesn't allow me to that.

Let me explain, what I really want to do

Let HumanResourceProject at : http://ift.tt/1SiLmxH
sample controller is api/hr/LeaveRecord/GetByEmployee/
Let CRMProject at : http://ift.tt/1l3BrB9
sample controller is api/crm/Customers/GetByRegion/
Let Gateway at : http://ift.tt/1SiLoWh

I want my gateway to handle requests like
1. http://ift.tt/1SiLoWjapi/crm/Customers/GetByRegion/
or
http://ift.tt/1SiLoWjapi/hr/LeaveRecord/GetByEmployee/

2. Make some controls like ip/access/browser etc.

3. I want to call correct api controller api/crm/Customers/GetByRegion/

4. Return response of called api's controller.