okay, here it goes.
i just did this, step by step in about 5 minutes (minus installing open office which i thought i had installed, writing the post and creating and uploading pictures to flickr).
created text file named test_sort.txt with this content.
(you could simply copy your text from your document to the plain text editor that comes standard with osx)
1. dr strangelove
2. amelie
3. alien
4. ronin
5. life is beautiful
6. princess mononoke
7. the apartment
8. unbreakable
9. the seven samuri
10. north by northwest
11. the pianist
12. its a mad mad mad mad world
13. the shining
14. dogma
15. stripes
renamed the text file as test_sort.csv
opened that file with open office's "calc"
this opens a text import dialog/window
choose "space" under seperator options.
the result will be a basic spreadsheet.
mine actually even dropped the periods after the numbers. the only thing that looks clumsy is that titles with more than one word are in seperate cells. though you could fix that. or, you could avoid this ahead of time by doing a find replace on the text document.
find ". " (the period and space after all your numbers), and replace with ",".
then instead of space delimited under seperator options, you'd select comma delimited.
your result should look something like this.
you can then select all cells and sort by the column that contains the first word of all the titles.
select the "button" indicated by the arrow or apple+a to select all.
then sort by going to data > sort... and sort by column b (or whatever column it turns out to be for you).
you can then just save this as a .csv file again. and open in either any spreadsheet program or text editor.
i'm guessing there may be a difference or two between open office for windows and neo office for mac, but i'd guess with this instruction you should be able to easily find your way through it.