Probably not the best way, but at least, the following is quite straightforward:

Code:
Public Sub SortAscIntCol(ByRef Col As Collection)
    Dim i As Long, j As Long, k As Integer

    For i = 2& To Col.Count
        k = Col(i)

        For j = i - 1& To 1& Step -1&
            If k >= Col(j) Then
                Col.Remove i
                Col.Add k, After:=j
                GoTo 1              '<-- For efficiency reasons
            End If
        Next j

        Col.Remove i
        Col.Add k, Before:=1&
1   Next i
End Sub