What is the exact model of PIC you are using in your design?
The VDIP1 offers three methods of interfacing with its host MCU, UART, SPI or Parallel. The UART method of interfacing would most likely be the simplest if you have limited experience with PIC programming.
Here is an example of interfacing a VDIP1 with a PIC18F:
The VDIP1 is designed around the VNC1L device. The following is an FTDI appnote demonstrating the interfacing of the VNC1L dev board, using the UART, to a PIC18F dev board. You should be able to easily adapt the connections and code to the VDIP1.