How to access a computer from LAN from another computer on my network through Command Prompt or DOS.?

Are you actually running DOS as the operating system on the system you're working from? If so, this will be a bit tricky, getting all the TCP/IP drivers to work in under 640K can be a pain. If you are running Windows, I would simply map a drive in Windows Explorer and then use that mapped drive letter to get to the shared resource.