Sort Combo Box by UDC code

By default, Combo Box list values are sorted by UDC description.

Is there any way to sort the list by UDC code. When I unchecked the 'Sort' property of Combo Box,

it gives the same result.

For example, UDC Floor(59/Fl) have the following values,

1    First floor

2    Second floor

3    Third floor

4    Fourth floor

5    Fifth floor

When the Combo Box loads, it gives the following sequence,

Fifth floor

First floor

Fourth floor

Second floor

Third floor

Now, how can I sort by the UDC code ?