[dba-SQLServer] Append several fields into one

I am trying to append all of the pieces of an address into a single address string.  As an example, 
if I have the address:

121 S. Main Street NE Apt #201

this address will be stored with standardized spellings of all the parts into a set of fields:

121
S
Main
St
NE
Apt
201

I need to get this all back into a single field.  Understand however that lots of those pieces might 
be missing in any given address.  For example the next field might be:

121

Main
St

Ste
1342

So... I need to get all the pieces back into a single address field.  If a piece exists then it 
needs padding around it so I don't end up with:

121MainStSte1342

But if a piece does not exist then I do not want the padding for that missing field.

I am assuming that I will be using a stored procedure.  Pass in the database, table, 
UnifiedAddressField, then all of the field parts.

It seems clumsy to do it this way, not to mention record by record, for 50 million records... well...

There must be a better way.  Has anyone on the list done this before?

-- 
John W. Colby
www.ColbyConsulting.com