Help with transport agent - save attachment

hi there

i am migrating Exchange 2007 to 2010 at the moment. we use an OnSave eventsink that is attached to a public folder to save all incoming attachments to disk. 

I need to re-create this in 2010, and as far as i can see, EventSink has been discontinued. 

I have been looking at transport agents - but i have no programming background, and i can't see any way to apply a transport agent to a specific mailbox? 

So i suppose my question is twofold:

1) could someone help me write a transport agent for saving an attachement to file

2) if i then have this transport agent, can it be applied to a specific mailbox / PF ?

Thanks!

Ian