Yes, that would work(but the other settings are also copied). As for the walkthrough:
-Requirements: any hex editor, windows calculator
1. browse to c:\Users\[username]\Documents\My Games\FINAL FANTASY XIV\
2. make a backup of config.sys
3. start the config tool and write down your current resolution
4. open windows calculator and change to programmer view
5. set it to "dec" and enter the resolution width
6. set it to hex and write down the inverted hex number (e.g. 780->8007, 1234->3412)
7. open config.sys with a hex editor and look for that number
8. pick a resolution width you want a do step 5-6 with it
9. overwrite the number in the file with the new number
10. repeat step 5-9 with height

Btw I still have 1776x1000 available in my general settings. So it's not a problem with the game. It's most likely the monitor driver :P