Como puedo modificar esta macro para poder agregar más columnas en listbox

Disculpen mi macro es:

Dim i, items, xEmpleado

Private Sub btn_Buscar_Click()

If Me.txt_Buscar.Value = Empty Then
MsgBox "Escriba un registro para buscar"
Me.ListBox1.Clear
Me.txt_Buscar.SetFocus
Exit Sub
End If

Me.ListBox1.Clear

items = Range("Tabla1").CurrentRegion.Rows.Count
For i = 2 To items
If LCase(Cells(i, 1).Value) Like "*" & LCase(Me.txt_Buscar.Value) & "*" Then
Me.ListBox1.AddItem Cells(i, 1)
Me.ListBox1.List(Me.ListBox1.ListCount - 1, 1) = Cells(i, 2)
ElseIf LCase(Cells(i, 2).Value) Like "*" & LCase(Me.txt_Buscar.Value) & "*" Then
Me.ListBox1.AddItem Cells(i, 1)
Me.ListBox1.List(Me.ListBox1.ListCount - 1, 1) = Cells(i, 2)
ElseIf LCase(Cells(i, 3).Value) Like "*" & LCase(Me.txt_Buscar.Value) & "*" Then
Me.ListBox1.AddItem Cells(i, 1)
Me.ListBox1.List(Me.ListBox1.ListCount - 1, 1) = Cells(i, 2)
End If
Next i
Me.txt_Buscar.SetFocus
Me.txt_Buscar.SelStart = 0
Me.txt_Buscar.SelLength = Len(Me.txt_Buscar.Text)
Exit Sub

End Sub

Private Sub btn_Eliminar_Click()
Dim Fila As Integer
Dim Final As Integer

If Me.ListBox1.ListIndex = -1 Then
MsgBox "Debe seleccionar un registro"
Exit Sub
End If

'Buscamoos la última fila
Fila = 2
Do While Hoja1.Cells(Fila, 1) <> ""
Fila = Fila + 1
Loop
Final = Fila - 1

If MsgBox("¿Seguro que quiere eliminar este Registro?", vbQuestion + vbYesNo) = vbYes Then
For Fila = 2 To Final
If Hoja1.Cells(Fila, 1) = xEmpleado Then
Hoja1.Cells(Fila, 1).EntireRow.Delete
Exit For
End If
Next
Call btn_Buscar_Click
MsgBox "Registro eliminado", vbInformation + vbOKOnly
Else
Exit Sub
End If
End Sub

Private Sub ListBox1_Click()

'Determino que cuando selecciono un item,
'el valor seleccionado, sea asignado a la variable xEmpleado

items = Me.ListBox1.ListCount
For i = 1 To items - 1
If Me.ListBox1.Selected(i) Then
xEmpleado = Me.ListBox1.List(i)
End If
Next i

End Sub

Private Sub UserForm_Initialize()
'Le digo cuántas columnas
ListBox1.ColumnCount = 3
'Asigno el ancho a cada columna
Me.ListBox1.ColumnWidths = "100 pt;50 pt;50 pt"
'El origen de los datos es la Tabla1
' ListBox1.RowSource = "Tabla1"
End Sub

Private Sub CommandButton1_Click()
Dim Fila As Integer
Dim Final As Integer
Dim i As Integer

For Fila = 1 To 1000
If Hoja2.Cells(Fila, 1) = "" Then
Final = Fila
Exit For
End If
Next

For i = 0 To ListBox1.ListCount - 1
Hoja2.Cells(Final, 1) = ListBox1.List(i, 0)
Hoja2.Cells(Final, 2) = ListBox1.List(i, 1)
Hoja2.Cells(Final, 3) = ListBox1.List(i, 2)
Hoja2.Cells(Final, 4) = ListBox1.List(i, 3)
Final = Final + 1
Next

End Sub

Private Sub CommandButton3_Click()
For t = 0 To ListBox1.ListCount - 1
suma = suma + CDbl(ListBox1.List(t, 1))
Next
MsgBox "la suma de la columna 2 es de: " & suma
End Sub