Seperate bookmarked sections of a PDF?

Hi All,

I have tried to find an answer to this but can't yet, I have a new software programme that generates invoices I need for work and exports them as a single PDF document with each customer having a 'bookmark' section for their invoice. I can print the document section by section but I need to be able to email some customers their invoices instead of posting hard copies. I cannot find a way that I can extract a bookmarked section to it's own document so I can send a customer their invoice not everyones!

If anyone could help I would be extremely grateful.

Cheers