I think SSID is setup in your config scripts (/etc/pci/wireless.opts or something like that). For encryption... the same thing... If you find config scripts, evrything will be easier
About startup script, I can't tell you precisely because I've never used MDK10... but if module insertion at startup is enough for you see /etc/modules.conf and of course "man modules.conf"... If you want to do other than inserting modules, see /etc/init.d directory and also /etc/rc5.d/ if your default runlevel is 5...