Same series, different coloured line?

[Jay]

If I have a continuos data series populating a chart, is there any way of
having some of the values plot in a different style line?

i.e I have 24 values, half of which are extrapolated which I format in red.
They are all the same series but I want the red formatted, extrapolated
values to chart as a dotted line.

Is there any quick way of doing this without breaking it into more than one
series?

Any help greatly appreciated.

Thanks,


Jason