If it is a WINNT, WIN2000, or WINXP system then you can simply map to his computer using the UNC and IP address.
\\<IP ADDRESS>\<SHARE NAME>
Windows authentication is used as rights verification so you would need a local admin account on your brothers system and he would need to share out a folder for you to upload to, or you could utilize the default admin share of <VOLUME NAME>$.
Thou shalt not follow the NULL pointer, for at its end lay madness and chaos.
-Shroud, CCNA, MCP