You'll need Office Developer Edition or Access Developer Extensions. The alternative is to redevelop the app using VB - which would be more expensive than using the first option
In this case, with the use of 2 listboxes you could possibly use the sample that I posted before:
http://www.access-programmers.co.uk/forums/showthread.php?t=107665
where you could modify this sample as per the MoveRecord sample.
Here's a function that may be useful
Function fCardinalDate(bytDay As Byte) As String
Select Case bytDay
Case 1, 21, 31
fCardinalDate = bytDay & "st"
Case 2, 22
fCardinalDate = bytDay & "nd"
Case 3, 23
fCardinalDate = bytDay &...
Maybe you should try the following for starters:
1) repair / compact the current database
2) create a new blank database and import all of the objects from the "bad" database into the new one.