Your approach will insert unnecessary tabs before the line breaks - and in some situations that could affect the overall layout.
For a macro, try:
Code:
Sub Demo()
Application.ScreenUpdating = False
With ActiveDocument.Range
With .Find
.ClearFormatting
.Replacement.ClearFormatting
.Forward = True
.Wrap = wdFindContinue
.Text = "^g^g^g"
.Replacement.Text = "^&^l^l"
.Execute Replace:=wdReplaceAll
.Text = "^g^l"
.Replacement.Text = "^t^&"
.Execute Replace:=wdReplaceAll
.Text = "^g^t"
.Replacement.Text = "^t^&"
.Execute Replace:=wdReplaceAll
End With
End With
Application.ScreenUpdating = True
End Sub