C'est faisable mais galère sur 2003. Sur 2007 tu feras un truc du genre
ThisWorkbook.Sheets(Array("Sheet1", "Sheet2", "Sheet3")).Select
ActiveSheet.Range("A1:F2").ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
"C:\First.pdf", Quality:=xlQualityStandard, IncludeDocProperties:=True, _
IgnorePrintAreas:=False, OpenAfterPublish:=True