I sometimes find it is easier to do stuff with a macro rather than a formula. I guess if I had better formula skills that would be different. I also think I read somewhere that if a task can be completed with a formula rather that a macro, you should use the formula. I am sure one of the pundits on this site will chime in on the correctness of this.
Are you looking for the "Zip Range" to be all in one cell separated by commas or would you prefer them going down the column.
From your example assuming the "AgentName" is column A and the "Zip Range" is Column G, then the following two codes will, as noted in the code do one or the other. The caveat with putting all the zips in one cell is that 1) there is a limit to how many characters a cell can contain and 2) a lesser number of how many characters a cell will display. The formula bar however will show all the characters.
Code:
Sub zipRng()
'All zips in Cell G2
Dim zip As Long, i As Long
Dim zipr As String
For i = Range("C2") To Range("D2")
zipr = zipr & ", " & i
Next
zipr = Mid(zipr, 2)
Range("G2") = zipr
End Sub
Code:
Sub zipRng2()
'All zips going down colunm G
Dim qzip As Long, i As Long
Dim arrZip
qzip = Range("D2") - Range("C2") + 1
ReDim arrZip(1 To qzip, 1 To 1)
For i = 1 To qzip
arrZip(i, 1) = Range("C2") + i - 1
Next
Range("G2").Resize(UBound(arrZip)) = arrZip
End Sub
I hope this helps some...