To save file base on cell range address as excel
Sub Save to excel()

Dim s As String
Dim path1 As String

path1 = ThisWorkbook.Sheets("Input billing").Range("b9").Value
s = ThisWorkbook.Sheets("sheet").Range("b10")

 Application.DisplayAlerts = False
 Sheets("sheet").Copy
 ActiveWorkbook.SaveAs (path1 & "Billing " & s & ".xlsx")
 ActiveWorkbook.Close
Application.DisplayAlerts = True

End Sub