Telephone Answering Service Application for Asterisk

In need of a programmer who has experience writing programs that use the Microsoft Windows API Telephony Application Programming Interface (TAPI) & SIP. We are interested in having an answering service call handling and scripting software developed identical to [login to view URL] but with added features that is designed to work with asterisk Look over [login to view URL] to get a feel for the functions of the application. Application must include billing module as well as a scripting module where representative can build questions and answers to questions within user profile Application will be used in conjunction with a Fonality asterisk pbx The systems gui is hosted so user must be knowledgeable of creating an application that can run in conjunction with the hosted gui. Your suggestions are most welcomed to derive at the most suitable solution The program should run on windows XP, Vista and Windows 7 environment. We would prefer C++ with a nice GUI. I will provide a detail list of features the application should include at the beginning of the project. Freelancer should be VERY PROFICIENT WITH ASTERISK AND WINDOWS TAPI APPLICATIONS