you can't but you can script the job created through Maintenance plan. In 2005, It works like a SSIS package so you change configuration and deploy wherever you want i.e to other server and file system.
You can not script for Maintanance Plan(MP), but you can script out an indivual Job.
In SQL 2005 there is new and great feature that you can create MP in the form of SSIS package. means you can add as much information you need for the job.