Custom User Interface for existing desktop application

I will need you to create a moderately custom user interface for an existing desktop application. The current coding is in C++. This is not a basic ui, it will require a bit of artistic touch to replicate the look I'm seeking (A screen shot will be provided). The ui will also need to be compatible for both windows and mac computer users. In addition to providing the ui you will need to be able to display a portion of the coding over a full screen game window, do not message me if you do not know how to do this as the deadline is very strict. More information will be provided if I chose to interview you. The project will need to be done in a very timely manner, within 4-7 days, but obviously if it can be done sooner that is preferred. [This part is removed by the Freelancer.com admin]. Im offering $65 to complete this project.