This really has nothing to do with the PIC. You have exactly the same situation of you were connected to any other device (another PC for example) through a serial link.
I would start by defining or understanding the communication protocol that would sit above the RS232 link - that commands are required, what information is begin passed each way, how often etc.. If the PIC code already exists then this will be known; if you need to code the PIC as well then you need to go back to what the PIC is there to do and design everything from there.
You can then use whatever tools and techniques you are required to use within your organisation or choose whatever else you may thing is reasonable for the situation and go from there.
Basically, what you do on the PC side has nothing to do with the PIC provided you both stick to the protocol.
Susan