first you will need to read and understand THIS to learn the basics of integrating a program with paltalk.
Once you understand what is being taught in the above post, then you can start applying what you have learned and use reshack to figure out the command to send to open a Send File dialoge box.
If you understand VB and can follow code, you can use one of the following as a starting point so your program will work with multiple versions of the paltalk client:
VB 6
VB 2005 detect pal version
and
VB 2005 find subform wHnd
good luck
autopilot