I have come up with a work around for this Horizontal Page Numbering challenge.

Since my Horizontal pages for the report I am working on will only ever extend to a 2nd page, I just used a text object that has a "{Horizontal Page Number}" embedded into it.
I then used suppression logic to hide the text object when there is no horizontal Page generated.


Example of text object:
Horizontal Page {Horizontal Page Number} of 2

The above text item was used along with the Special Field: {Page N of M}