adding a single point that stands out to a surface plot

hi,

i created a simple program to take a list of (x,y,z) points and put them
on a 3D surface plot with the domain (x,y) and the range z, or
FunctionType:

 (x,y) -> z

this program does this by using a Irregular2DSet as the domain, a
FlatField mapping the FunctionType to the domain, and a DataReference
mapping this FlatField to a DisplayImplJ3D.

All I would like to do is add a simple way to this program that will put
a single point on the graph, with a larger size than the other points
and a color that stands out.

I was curious what the easiest way to do this would be?

I am confused about 2 things:

how do I go about it without connecting that extra point in with the
rest of the surface plot?

how could I have a single point, possibly with an (x,y) value that is
not in the current Irregular2DSet domain, be on the same plot.

maybe someone on here can help clear things up.

any help would be appreciated.

Thanks,
-Mike