http://modthemachine.typepad.com/my_weblog/2009/01/translating-files-with-the-api.html
This blog post contains the link to the translator reporter vba macro developed by Brian Ekins.
This code generates the list of all available translator Add-Ins, their Add-In ID, and the options supported by each Add-In.
You should use Sheet.Size and Sheet.Orientation read/write properties.
Available values are described in the Inventor API help file.