Communication between host and guest

Hi there,

I am running Parallels 5 on Mac OS X 10.6.2 with a Windows XP SP3 guest system.

I have a program that runs in windows that takes input from a usb device, and then sends keystrokes to other applications to send commands. The software opens on the guest OS and will read the USB device just fine, but what I am having problems with is a way to control other pieces of software on the Mac system.

My question: is there any way to read keystrokes sent from an application on the Guest OS from the Host OS? If I have a program sending out a stream of characters on the Windows OS, is there a way I can have those keystrokes become 'seen' by an application on the Mac?