Bonjour,
Sans information, essaie ainsi :
Option Explicit
'Fileformat mac :
'xlsx = 52
'xlsm = 53
Sub SaveAsNewWorkbook()
Dim sPath As String, sFilename As String
sPath = ThisWorkbook.Path & Application.PathSeparator
sFilename = Range("A1").Value & ".xlsx" 'ou .xlsm"
Workbooks.Add
ActiveWorkbook.SaveAs sPath & sFilename, 52 'ou 53
End Sub