Authenticating on a local network computer.

[Theriex]

I have 2 computers set up here on a network, both in the same workgroup how do I authenticate from one computer on to the other.

Lets say computer1 is //Computer1 and computer2 is, you guessed it //Computer2

I want to be able to connect to //Computer2 programmatically. It does require a username/password.

Please help, this is driving me nuts.