Well ... I assume you'd have to double-process the raw file.
Once as normal
Once for the sky only, with REALLY aggressive contrast, so the beam stands out.
Then combine them as layers in PS.
But the trouble is, such aggressive contrast would almost certainly bring out some pretty nasty noise. A dark blue sky will usually harbour noise, and the risk of exaggerating it would be great.
So try it, but you might find that the "faking it" route is better.