modelling prestressed curved beam in sap2000

[valjhun]

hello,
i would like to model a prestressed concrete beam in sap2000 v17.
beam is curved (circular curvature - radius 1000m) in X-Y plane (gravity is -Z) and has one span (supports are at its ends)

i have used draw frame/cable/tendon->line object type: curved frame to draw the beam.

but i have a problem modelling a tendon.
i want tendon to be parabolic along the beams length (plane 1-3 in local coordination system of beam element; axis 3 points in direction of gravity)
now i dont know how to model tendon so that it will also follow beam in X-Y plane or 1-2 in local coordination system of beam.


i hope it is understood what i want to know and i also appologize for my english.

regards,
valjhun