Risolvi modificando l'array nella procedura.
Ad esempio:
codice:
Private Sub Command1_Click()
Dim Arr1(2) As Long
Dim Arr2(2) As String

Arr1(0) = 1&
Arr1(1) = 2&
Arr1(2) = 3&
Call Procedura(Arr1, Arr2)
End Sub

Private Sub Procedura(ByRef Arr1() As Long, ByRef Arr2() As String)
Const AscUno As Long = 48&
Dim Cont1 As Long

For Cont1 = 0& To UBound(Arr1)
  Arr2(Cont1) = Chr(AscUno + Arr1(Cont1))
Next Cont1
End Sub