Well, it's rather simple. Both NERO_CAPABILITIES and NERO_MEDIA_TYPE define a set of bits. Now, MediaSupport property indeed returns a long, but it should be interpreted as a combination of NERO_MEDIA_TYPE flags. Same for Capabilities property.
So, for instance... Lite-On LTN483S 48x Max Capabilities = 389 means NERO_CAP_IDE_BUS + NERO_CAP_UNDETECTED + NERO_CAP_READ_CD_TEXT + NERO_CAP_ALLOWED.
CDWRITER IDE5232 Media Support = 32833 means NERO_MEDIA_FPACKET + NERO_MEDIA_MRW + NERO_MEDIA_CD.
Now, how you do this programmatically really depends on the language used. Generally, you should AND the value with each of the flags. A non-zero results tells you that the flag is set.