Vba - extract values and list once - list

Question

I have a spreadsheet with two raw data sheets on separate excel tabs that has been extracted from a finance system, containing values that represent cost codes. The dataset on both tabs is quite large and the codes that I want listed just once are repeated multiple times. I want a macro that will scan these two relevant columns (say column A on both sheets) and list the cost codes once in numerical order on a third sheet.
I've searched this site but can't seem to find a code that does the above completely.
Thanks in advance

Answer 1

This may not be the fastest implementation possible, as it mostly relies on VBA operations to do the work, except the final sort. Has not been tested.
Sub AppendUnique(ByVal W1 As Worksheet, ByVal W2 As Worksheet, ByVal R1 As Long, ByVal R2 As Long, ByVal C1 As Long, ByVal C2 As Long)
' Append values from an unsorted column to a new unique but unsorted column
Dim V1 As Variant, V2 As Variant
Dim I As Long
V1 = W1.Cells(R1, C1).Value
While Not IsEmpty(V1)
I = R2
V2 = W2.Cells(I, C2).Value
While Not IsEmpty(V2)
If V2 = V1 Then Exit While
I = I + 1
V2 = W2.Cells(I, C2).Value
Wend
W2.Cells(I, C2).Value = V1
R1 = R1 + 1
V1 = W1.Cells(R1, C1).Value
Wend
End Sub
Dim W1 As Worksheet, W2 As Worksheet, W3 As Worksheet
Dim C1 As Long, Dim C2 As Long, Dim C3 As Long
Dim R1 As Long, Dim R2 As Long, Dim R3 As Long
Set W1 = Worksheets("Sheet1") ' Source 1
Set W2 = Worksheets("Sheet2") ' Source 2
Set W3 = Worksheets("Sheet3") ' Destination
C1 = 1 ' Column on Sheet1: Source 1
C2 = 1 ' Column on Sheet2: Source 2
C3 = 1 ' Column on Sheet3: Destination
R1 = 1 ' Starting Row on Sheet1: Source 1
R2 = 1 ' Starting Row on Sheet2: Source 2
R3 = 1 ' Starting Row on Sheet3: Destination
AppendUnique W1, W3, R1, R3, C1, C3
AppendUnique W2, W3, R2, R3, C2, C3
W3.Range(W3.Cells(R3, C3), W3.Cells(R3, C3).End(xlDown)).Sort