Well the whole idea is that you use bracketing to make a couple of shots at different exposures. Then software merges them into one. For example:
Photo with very overexposured foreground , overexposured subject and correctly exposured sky
+
Photo with overexposured foreground , correctly exposured subject and underexposured sky
+
Photo with correctly exposured foreground , underexposured subject and very underexposured sky
=
Photo with correctly exposured foreground , correctly exposured subject and correctly exposured sky
I have been looking around for some good HDR software, so you won't mind if I'll wait for some software recommendations with you?
P.S. sorry for misstating your use of a POL filter.