Not sure if I understand entirely.
If you have the query already built, you can use a DLookup:
=DLookup("[AddressLine]","qryAddress","[PersonID]=" & PersonField
If you don't have the query built, and want it displayed on the form, you would enter something like:
=[FirstName] & ", " & [LastName] & ", " & [StreetAddress] & ", " & [City]... etc.
If you want it done in a query and don't have the query built, you would use something like:
AddressLine: [FirstName] & ", " & [LastName] & ", " & [StreetAddress] & ", " & [City]... etc. Assuming all those fields are added to the query.
Let me know if I missed your point.