DVD Subtitles

1.8GHz CPU, Win XP Pro machine.
I want to replace English subtitles with Maltese ones. I have extracted an English DVD subtitle via SubRip in the .srt file type. Then I opened the .srt file in Word 2003 and translated it to Maltese.
Maltese uses all the keys of the English (UK) keyboard plus 4 extra characters, c,g,h,z, each with a dot on top, which can be accessed by shortcuts ALT+C, ALT+G, ALT+ H, and ALT+Z. These show correctly in Word 2003 .doc file but NOT when saved as a Plain Text .txt, file as required by programs Subtitle Creator and Subtitle Workshop to recreate the .srt file,for their further processing.
Any ideas ideas as to how to save these 4 characters as a plain text file.