see Re: PDF GetInfo( for an approach that can be used in your case.
I mean using Win32::OLE to manage Acrobat doing things for
you. Exact commands that needed for you can be found at Acrobat
SDK documentation or just in Acrobat.tlb file which
usually exist in a directory where Acrobat is installed.
Also I completely agree with abstracts,
it is a matter of fact that Adobe invented really imperfect security
system.