What database is it? Each RDBMS has its own set of character
and numeric functions that my allow you to manipulate the data in
the ORDER BY clause.
Questions to answer:
Is the format the same for all entries, such as number,
letter, dash, number, etc? If so, do you only need to sort by the
number following the dash, or by the first number and then the
number following the dash?
At any rate, there are ways to do things like taking a
substring of the field from a particular starting character, then
converting that substring to a number and using the resulting value
in the ORDER BY, etc. Using regular expressions also come to mind.
More detail from you on your requirements may yield more
comprehensive suggestions.
Phil