You need to use the TopLeftcell property of the CommandButton. The following code is written on the assumption that the command button is contained within one cell, if it is in more than one cell then you may need to modify as appropriate
Code:
Private Sub cmdTest_Click()
Dim i As Long
cmdTest.TopLeftCell.Select
i = cmdTest.TopLeftCell.Row
ActiveSheet.Rows((i - 1) & ":" & (i - 1)).Insert Shift:=xlDown
End Sub
HTH,
Maccas