I want to make an alias that will be filled by different actors depending on who gave you the quest. For instance, there are 3 people who will give you the same quest, you can talk to either one of them to get the quest. The problem is the final quest objective is going to say something like "return to " but I don't know how to do this.

&--#60;Alias=AliasName&--#62;

Put that into your objective. Bethesda like to use QuestGiver as the NPC alias is almost all of their quests. Using the name of your Alias in place of AliasName in there will show their name. However I recommend using:

&--#60;Alias.ShortName=AliasName&--#62;

That way it'll use whatever the NPC's short name is; usually their first name.

So your objective would be:

Return to to complete your quest.