Why don't you tell us the name of the quest, the place and the name of the boss? These are important details, and leaving them out makes it harder to help you.
And please tell us what are you looking for? A cheat? What weaknesses the boss may have? A non-combat way to resolve the quest?
This is Morrowind, some combat will be difficult at lower levels. The best solution is usually just to go do other stuff, level up, and then come back and get that difficult boss. IMHO adapting your play style to this will be more fulfilling and rewarding than trying to beat hard bosses at low levels.