A simple why to allow input of another language's special character is to add a keyboard layout map. You will need to memorize the location of the of the special characters on your standard keyboard:
- Go to: PuppyMenu > Setup > Mouse/Keyboard Wizard
- click on 'Advanced Xorg configuration', 'Okay', 'layouts'
- select to 'add' if you want an additional keyboard layout
- select the language you require, click on 'Okay'
- click on 'Yes', 'exit'
Now if you install fbxkb, you can click on the flag to switch keyboard between languages