I will post my solution to this question, but maybe others have found a better way.
I wanted to obtain the number of pages in a pdf document using VBA.
I reviewed similar [vba] and [acrobat] questions, but I did not find a stand alone solution. After reviewing other posts, Adobe Acrobat's SDK, and the VBA object browser, I learned enough to piece together this solution.
I am running Excel 2013 and Adobe Acrobat 9.0 Pro.
I understand its ok to answer my own question.
This solution works when Excel 2013 Professional and Adobe Acrobat 9.0 Pro are installed.
You will need to enable the Adobe object model: Tools -> References -> Acrobat checkbox selected.
Adobe's SDK has limited documentation on the GetNumPages method.
'with Adobe Acrobat 9 Professional installed
'with Tools -> References -> Acrobat checkbox selected
Sub AcrobatGetNumPages()
Dim AcroDoc As Object
Set AcroDoc = New AcroPDDoc
AcroDoc.Open ("C:\Users\Public\Lorem ipsum.pdf") 'update file location
PageNum = AcroDoc.GetNumPages
MsgBox PageNum
AcroDoc.Close
End Sub