Copy this function into a standard module (not form, report or class) and name the module something other than the name of the function:
Function AdjustProcNum(strTableName As String, strFieldName As String, lngNewNum As Long)
Dim strSQL As String
Dim rst As DAO.Recordset
strSQL = "Select [" & strFieldName & "] From [" & strTableName & "] " & _
"ORDER BY [" & strFieldName & "]"
Set rst = CurrentDb.OpenRecordset(strSQL)
Do Until rst.EOF
If rst(strFieldName).Value >= lngNewNum Then
rst.Edit
rst(strFieldName).Value = rst(strFieldName).Value + 1
rst.Update
End If
rst.MoveNext
Loop
MsgBox "You can now enter the new process number " & lngNewNum, vbInformation
rst.Close
Set rst = Nothing
End Function