How to set font size with PCL?

I need to set several options on a printer using PCL -
basically, I want to print something in landscape format
using a fixed width font - probably 8 or 10pt size.

So far, setting the landscape format works, but all I
have read about setting the size was not that clear.

Can I just set the point size (or primary height), or
do I need to set the pitch and typeface as well?

Do I need to set the primary spacing to be fixed also,
or would that be the default?

tia,
Bill