(
local pt1 = point pos:[50,50,0] , pt2 = point pos:[10,45,0],
p = pt1.pos, vo = pt2.pos , d = distance p vo , vi = p+(normalize (p-vo))*d,
r = d/0.551915024494, -- http://gorkamendieta.es/wordpress/maxscript-circle-using-bezier-curves/
m = matrixFromNormal (normalize (vo-p)) , c = p+m.row1*r, -- there should be better solution to get the vector (m.row1)
cr = circle radius:r pos:c dir:-m.row3
in coordsys local rotate cr (AngleAxis -90 x_axis)
addModifier cr (Edit_Spline())
select cr ; max modify mode ; subObjectLevel = 1
)