Hi, the irda signal is not modulated; so, you first need to get rid of the TSOP-IR-Receiver.

Adding irda capability to a PIC could be achieved a number of ways. Microchip themselves have irda codec solutions. Or, look up www.sirpic.com. The guy there, Ravi, specializes in Micro-to-irda solutions in varying degrees of customization. At this site, you'll also find a software-only irda implementation for PICs contributed by another person.

Regards

Anand