Windson:
Sorry to be late with my answer - I was on vacation.
I believe this desire can be fulfilled, yes.  

In the table you can simply use conditional formatting, to give the cell an
outstanding colour, a bold border or any formatting effect you want to apply.
Simply select from the menu Format/Conditional Formatting...

In the graph: create two new data series from yr original data set, both
with IF statements with complementary conditions.  Example: say you want to
highlight values >100.  Yr original data series in A, set up the two series
in B and C.  B as IF(A>100,A,NA()) and C IF(A<=100,NA(),A).  Don't plot A (I
assume XY scatter chart), but B and C instead.  The NA() values are ignored,
and the two series complement each other.  If u hv only one value >100, this
will appear as different colour.  You can change the marker.  Of course this
principle can be adopted to other ways (e.g., a circle around an data point t
highlight, or an arrow pointing to a particular point.)
HTH,
Henk