neporadim ti v c+, ale nize je algoritmus ve VB, ktery si preved do c+:

Function DecToZ(ByVal DecNum As Double, ByVal z As Byte) As String
'z je zaklad ciselne soustavy
Dim tmp As String, tmp1 As Double, tmp2 As Double, tmp3 As Double
  tmp = ""
  tmp1 = CDbl(DecNum)
  Do
    tmp3 = Int(tmp1 / z)
    tmp2 = tmp1 - (tmp3 * z)
    tmp1 = tmp3
    If tmp2 > 9 Then tmp2 = tmp2 + 7
    tmp = Chr(tmp2 + 48) & tmp
  Loop While (tmp1 > 0)
  DecToZ = tmp
End Function