To open a PDF at page 100 the follow works
<path to Adobe Reader> /A "page=100" "<Path To PDF file>"
If you require more than one argument separate them with &
I use the following in a batch file to open the book I'm reading to the page I was up to.
C:\Program Files\Adobe\Reader 10.0\Reader\AcroRd32.exe /A "page=149&pagemode=none" "D:\books\MCTS(70-562) ASP.Net 3.5 Development.pdf"
The best list of command line args for Adobe Reader I have found is here.
http://partners.adobe.com/public/developer/en/acrobat/PDFOpenParameters.pdf
It's for version 7 but all the arguments I tried worked.
As for closing the file, I think you will need to use the SDK, or if you are opening the file from code you could close the file from code once you have finished with it.
answered 2011-03-27T18:14:16.717