Excel VBA - Combine rows with duplicate values in one cell and merge values in other cell

Question

I am trying to find duplicate values in one column and combine the values of a second column into one row. I also want to sum the values in a third column.

For examp

Answer 1

Merging rows by summing the numbers from column D and building a string concatenation from column C with a semi-colon delimiter based upon duplicate values in columns A and B.

Before¹:

        

Code:

Sub merge_A_to_D_data()
    Dim rw As Long, lr As Long, str As String, dbl As Double
    
    Application.ScreenUpdating = False
    With ActiveSheet.Cells(1, 1).CurrentRegion
        .Cells.Sort Key1:=.Columns(1), Order1:=xlAscending, _
                    Key2:=.Columns(2), Order2:=xlAscending, _
                    Orientation:=xlTopToBottom, Header:=xlYes
        lr = .Rows.Count
        For rw = .Rows.Count To 2 Step -1
            If .Cells(rw, 1).Value2 <> .Cells(rw - 1, 1).Value2 And _
               .Cells(rw, 2).Value2 <> .Cells(rw - 1, 2).Value2 And rw < lr Then
                .Cells(rw, 4) = Application.Sum(.Range(.Cells(rw, 4), .Cells(lr, 4)))
                .Cells(rw, 3) = Join(Application.Transpose(.Range(.Cells(rw, 3), .Cells(lr, 3))), Chr(59))
                .Cells(rw + 1, 1).Resize(lr - rw, 1).EntireRow.Delete
                lr = rw - 1
            End If
        Next rw
    End With
    Application.ScreenUpdating = True
End Sub

After¹:

        

¹_{Some additional rows of data were added to the original posted data in order to demonstrate the sort.}