How many values are in this list?
Does the value list use only a single field in Manage | Value lists?
If you only need one field and the list is fairly small (Say 50 or less...)
Then this method can be used:
Define a number field in your value table, SortOrder, Put simple, small numbers in this field to determine the order you want for your values.
Define a calculation field:
Substitute ( 10^SortOrder - 1 ; 9 ; " " )
Select text as the result type.
This calculation returns a single space character for a sort order of 1, 2 spaces for a sort order of 2, etc.
Specify this calculation field as the second field in your value list and specify that the values sort on this second field.