It's possible, but you must check if it performs good. Just break the column into pieces. If you have allways the same pattern (fname.lname) you could do something like:
SELECT SUBSTR(your_column, 1, LOCATE('.', your_column)-1) AS fname
,SUBSTR(your_column, LOCATE('.', your_column)+1) AS lname
FROM your_table
ORDER BY 1
or
ORDER BY 2
HTH