Hello @OpticalResearch,
As I understand your problem statement, you want to create an eyepiece that forms a virtual image of an object at infinity. This eyepiece also needs to satisfy some field-of-view requirement (that you describe as input). To set this up in Zemax, you can describe the EPD or float by stop size. The latter may be simpler but you’ll need to enable ray-tracing. The stop could be the aperture of the eye. You would then define wavelength, and the fields.
You can introduce a lens between the object and the stop. This could be a singlet, doublet, compound lens etc. Its clear aperture needs to satisfy your FOV requirements. The distance between the lens and the stop will need to be defined by you. For eyepieces, this is referred to as eye-relief or even more generally as an eye box.
To introduce the virtual image, trace the rays “backwards” from the stop to the image, i.e, a negative thickness. Again, you’ll have to specify the desired value to the virtual image.
I hope this helps.