Projecting a 3D arc on a 2D plane.

I have an arc in 3D that when viewed from the "Top" view in Microstation looks like part of an elipse (or maybe a spline). I need to remove elevation from the arc and keep it still looking the same.

So, the 3D arc has the following attributes:

primary axis: 8312.2831

secondary axis: 8312.2831

Start angle: 0 deg

sweep angle: 56.6508 deg

end angle: 56.6508 deg

rotation X: 85.9285

rotation Y: 66.4511

rotation Z: 157.1940

axis ratio: 1.0

i was able to approximate the result by tracing it and got the following 2D arc:

primary axis: 8312.2831

secondary axis: 235.7978

Start angle: -26.5394 deg

sweep angle: 56.6508 deg

end angle: 30.1114 deg

angle: 246.5041

axis ratio: 35.25174

I dont even know where to begin. Let me know if i need to explain this better...

Thanks in advance for the help.