BSpline Approximation with AppDef_BSplineCompute, how can i extract...

Hello,

For Bspline approximation i use the advanced approximation package AppDef, i created an instance from AppDef_BSplineCompute, and i use the ChangeValue()-method to obtain a AppParCurves_MultiBSpCurve, so far as i know, with creating an object from AppDef_BSplineCompute, the method approximate an bspline curve ans store it in AppParCurves_MultiBSpCurve, but

how can i now create an Geom_BSplineCurve-object to show this approximated curve, with the AppParCurves_MultiBSpCurve i can obtain the Knots and Multiplicities table, but not a curve returned as Geom_BSplineCurve. When i use the same method for Bezier curves, in AppParCurves_MultiBSpCurve i have a method "curve" with returning Geom_BezierCurve...

please help, im gonna crazy with this stuff, i use this approximation variant cause i can specify more paramters as in the high level packages like GeomAPI package.

thanks in advance