How to Access and Set Lan Card Properties?

i am planning to create a Visual Basic 6 program that will set(or configure) the Internet Protocol (TCP/IP) Properties of my PC's Lan Card to
1) Obtain an IP address automatically
2) Obtain DNS address automatically

any tips on what i need to learn and do or some source code will be helpful.

So you just want to resolve a IP from a DNS and visa versa ?

i want to make a software that can switch my Internet Protocol (TCP/IP) Properties from Using a specific IP address and DNS to -> Obtain IP address and DNS automatically and vise versa.

This Link should help :) Search for the file attached by HL should work nicely :D