sorting library of congress numbers

I have a table where one of the columns is a library of congress number.

I would like to be able to ORDER BY this column.

Currently, the column is a varchar.  Unfortunately, a normal string comparison

will not work.

First, has anyone done this already?

If not, I’m thinking I would need to:

1)       define a new type to hold LOC numbers.

2)       write a function that determines less than, greater than

It seems like I’m missing something here.  I have not yet defined a new

type…is defining less/greater part of that process?

Is there a simpler way to do this?

Any advice is appreciated.