CGAL users discussion list

I need a way to find a rational point on a circle,
which is as close as possible to a given circular point 
on this circle. A rational point is a point with rational
coordinates, the circle itself is rational as well (has
a rational center, and is constructed of three rational points);

The circular point has coordinates of the root_of_2 type,
and what i need is a point with quotient<MP_Float>;

The rational points on the circle are dense, as far as my
investigations go, and i think the function C.point_on_circle(double alpha, 
double epsilon) for a rat_circle C from the LEDA package would solve my
problem ( 
http://www.informatik.uni-trier.de/~naeher/Professur/LEDA/doc/MANUAL/rat_circle.html
 )

Does anyone have an idea how this could work, or even better:
can anyone share the LEDA source code for this function?? ;)

mfg, Wolfgang