Add an Adobe Pdf Reader Control to your window and script it like this...
ole_reader.object.loadfile('C:\Users\mdl.SECURITY_GROUP\Desktop\PB 15 beta new feature testing guidelines.pdf')
Or add a MS browser control and do this...
ole_browser.object.navigate('C:\Users\mdl.SECURITY_GROUP\Desktop\PB 15 beta new feature testing guidelines.pdf')
Look under the menu Insert->OLE.. and go to the Insert Control tab. You will see these controls in the list.
hth,
Mark