i am made a Unicode English Arabic (Arabic, Urdu, Farsi, Pushtu and Sindhi) multilingual base font on FC5.6. I assigned glyphs with proper standard Unicode value according Arabic, Arabic extended, Arabic presentation form A & B. but when i install this font in windows xp and work in MS OFFICE 2003 only Isolated Characters of Arabic can be typed. initial, medial and final character cannot be typed in MS WORD. I gave the font Open Type feature in this font Fina, med, isolate and initial, mark to base, mark to mark, case-sensitive & fraction features by MSVOLT. In the MSVOLT Proofing Test is correct but in Win XP font does not work (only isolated forms work/can be typed).
I see that you have already asked this question on the MS VOLT forums, which is where it belongs. FontCreator doesn’t support OpenType Glyph Substitutions.
Perhaps some users here have experience working with VOLT, but then they could just as well answer on the VOLT forums where more expert advice would be available.
Would it be worth checking using FontCreator 5.6 that in Format Settings… Ranges Unicode Character Ranges Edit… that the flags for Arabic, Arabic Extended, Arabic Presentation Forms-A and Arabic Presentation Forms-B are all checked? This is not intended as a rhetorical question: I am just wondering whether unchecked flags might produce the effects reported in the original question.
Try that and see if it helps. Reinstalling the font and reboting can sometimes help too, but for questions about making OpenType features work, it is best to ask on the VOLT forums.