You will need to create a scheduled agent that runs every day. During weekdays, it will abort immediately. On the weekend, it will need to retrieve the files to be attached, create a document, assign the recipients in the proper fields, make the subject and insert the attachments.
Be aware that this has to be a server operation, meaning that the server must have access to the files - either via the network, or in the Notes database that is concerned.
You can create a new database for this, or include the functionality in an existing application.
It would be good to have on hand a programmer with some experience in Notes and LotusScript. Failing that, experience of OO programming and VB will be enough.
Pascal.
I've got nothing to hide, and I'd very much like to keep that away from prying eyes.