Problem:
How do I programatically create a landscape PDF?

Solution:
If you're using Visual Basic, you can use the Orientation property of the Printer object to set landscape as in:

'set landscape orientation
Printer.Orientation = vbPRORLandscape

 

If you're using the Windows API, you can use the DEVMODE structure as described in knowledgebase article Q167345 available at:
http://support.microsoft.com/kb/q167345/