Which argument is needed for the setCurPoint-function?
I have looked in the help, and there is this example:
for point in points:
hou.pwd().setCurPoint(point)
But I get this:

add_pt = 1
hou.pwd().setCurPoint(add_pt)
return _hou.SopNode_setCurPoint(*args)
TypeError: in method ‘SopNode_setCurPoint’, argument 2 of type ‘HOM_Point *’

setCurPoint() expects argument that has hou.Point class, not just an index of the point

OK, thanks.
Than I have another question. Is it possible to access one specific point if I know it's number?

yes,
hou.Geometry.iterPoints()
and
hou.Geometry.points()

advantages of one over another are in help
http://www.sidefx.com/docs/houdini10.0/hom/hou/Geometry#iterPoints [sidefx.com]

it all depends on what you want to do, i cannot imagine the usage of setting certain point as current(other than in looping through all points), but maybe you have the reasons for it