On Windows : put a shortcut of your patch in C:Documents and SettingsAll UsersStart MenuProgramsStartup.
I use a small program call "wait" (wait.exe)because Window launches the patch before a lot of things, especially midi config etc... This program is easy to use, I wait a minute or a minute and half before launching my patch which is configured to work under Max/MSP.
On Mac : in Preferences-->Accounts-->Open +button and choose your patch.