Hopefully I have understood your question and this does what you need.
Code
Sub x()
Dim rngTemp As Range
Set rngTemp = Application.InputBox("Select cells to sum", Type:=8)
MsgBox Application.WorksheetFunction.Sum(rngTemp)
End Sub
Sub y()
Dim rngTemp As Range
Set rngTemp = Application.InputBox("Select cells to sum", Type:=8)
MsgBox Format(Application.WorksheetFunction.Sum(rngTemp), "$#,##0.00")
End Sub