Wine emulator is not as powerful as a standalone Windows or Windows that you can run on a virtual machine, but it is absolutely free and you can run some Windows applications with it right from your Mac. Here is how to install it:
How to install Wine on Mac OS X 10.6.2 (Snow Leopard)

You can run Replay Media Catcher on Mac OS using freeware WINE or WineBottler:
How to install and run Replay Media Catcher on Mac OS X (Snow Leopard)