You actually don't have to do anything. CommonDialog controll will change the printer object for you. The only thing you have to consider is if you want the common dialog printer to change the selected printer to be a default printer. So if you don't want it to change it then you have to use PrinterDefault property:
VB Code:
Private Sub Command1_Click()
With CommonDialog1
'make sure that CommonDialog will not change it
'to be a default printer
.PrinterDefault = False
.ShowPrinter
Printer.Print "hi"
End With
End Sub