I have only briefly tested this, it seems to work, but I can't guarantee
that there are no exceptions that I haven't anticipated ...

Public Function ToOrdinal(ByVal TheNumber As Variant) As String

   Dim strChar As String

   If Len(TheNumber & vbNullString) > 0 Then
       If Len(TheNumber) > 1 Then
           If Mid$(TheNumber, Len(TheNumber) - 1, 1) = "1" Then
               ToOrdinal = TheNumber & "th"
           Else
               Select Case Right$(TheNumber, 1)
               Case "1"
                   ToOrdinal = TheNumber & "st"
               Case "2"
                   ToOrdinal = TheNumber & "nd"
               Case "3"
                   ToOrdinal = TheNumber & "rd"
               Case Else
                   ToOrdinal = TheNumber & "th"
               End Select
           End If
       Else
           Select Case Right$(TheNumber, 1)
           Case "1"
               ToOrdinal = TheNumber & "st"
           Case "2"
               ToOrdinal = TheNumber & "nd"
           Case "3"
               ToOrdinal = TheNumber & "rd"
           Case Else
               ToOrdinal = TheNumber & "th"
           End Select
       End If
   Else
       ToOrdinal = vbNullString
   End If

End Function

Here's an example of it's use in a query (in production, it might be better
to use it in the ControlSource of a text box on the report, but a query is a
good way of testing it with a range of different numbers) ...

SELECT tblTest.TestNumber, ToOrdinal([TestNumber]) AS TheOrdinal
FROM tblTest;

This function should do what you want:

Function Ordinal_Numbers(P_Numeric As String) As String
Dim V_Ordinal As String
Dim V_Numeric As String
If Right(P_Numeric, 2) = "11" Or Right(P_Numeric, 2) = "12" Or
Right(P_Numeric, 2) = "13" Then
 Ordinal_Numbers = "th"

Else
V_Numeric = Right(P_Numeric, 1)

Select Case V_Numeric
 Case "1"
   V_Ordinal = "st"
 Case "2"
   V_Ordinal = "nd"
 Case "3"
   V_Ordinal = "rd"
 Case Else
   V_Ordinal = "th"
End Select
Ordinal_Numbers = V_Ordinal
End If
End Function

Call the function from a query like this:

OrdinalNumber: [YourNumberField] & Ordinal_Numbers(CStr([YourNumberField]))