Thank you for the quick reply...
Yes, I have thought of that option too. The issue I have (being a novice with parsing) is how you would position the city, when in fact it could be a different city. For example, 43017 here in Ohio falls into three counties and could be associated with potentially 3 cities. Thus if the city is different on the client record field, how would you know where to stop the extraction of the street address without also potentially pulling in the city too?
Say the client record says "Columbus" and the zip code look up says "Dublin".