Thanx ElDiablo, looks pretty clear!
Now... before posting this thread, this is what i had tried to do! Actually i did the opposite, i started with making the partitions in Windows, made a primary, formatted it NTFS, then made a second primary and left it unformatted. Then i connected the drive to the Mac (already had macfuse installed). The NTFS partition was recognized, but i couldn't see the unformatted one. So back to windows again, format the unformated as NTFS, then back to OSX again, i tried to erase the 2nd NTFS partition as HFS+, but hey presto... the result was that the whole drive (both 1st and 2nd partition) was HFS+ partitioned! Why the heck did that happen?