Function ConvertBase10ToBase2(ByVal Value As Long) As String
Dim lQuotien As Long, lRest As Long
' valeur positive
ConvertBase10ToBase2 = vbNullString
Value = Abs(Value)
' crée la chaîne
Do
lQuotien = Value \ 2
lRest = Value - (lQuotien * 2)
ConvertBase10ToBase2 = CStr(lRest) & ConvertBase10ToBase2
Value = lQuotien
Loop Until lQuotien = 0
End Function