Persian Handwriting Font
My Handwriting font, I developed myself. This is an Open type font compatible with Windows Farsi keyboard layout and contains standard Farsi glyphs. There are some Open type features you can use in Open type compatible softwares like Adobe CS series...
'Atronoush Bashang', A very good font designer and graphic artist and also a dear friend has updated this font with both Persian and Arabic digits. Now you can select your digit style in CS4/5...
Installation: Unzip the archive and copy the font file in your windows/fonts folder...
Ardaviraf has posted about this font in his blog...Thank you
O.K...No here's a simple How To Create A Font! 
Start: Have you designed a font? if no, first design a font! then come back and start again )
1: use a vector graphic program like Adobe Illustrator to draw individual glyphs in vector format...(many of font creation softwares also have vector features so try them to see if you're comfortable with...)
2: (using a font creation software like Fontlab or Font Creator or your choice...) open a font file, delete it's existing glyphs and insert your glyphs one by one into their respective cells...
3: align each of your glyphs to the baseline...
4: adjust the spacing before and after so that your glyphs match together correctly...
5: test the font using the software you're using...all the font creation softwares have a feature to test/preview the font and check for any mistakes or misplacements....
6: compile the font...install it in windows font folder and happy typing! )
Now...here is the advanced part...
say, you've design a font in Farsi language and you have designed a specific glyph for the combination of "KAF", "LAM", and "ALEF"....(I've done this in my own font above...open it and you'll see the glyphs...)...here is the question...how do you tell the font to replace any combination of "KAF", "LAM", and "ALEF" with your new glyph?...
First you must know about Opentype...a few years ago, Microsoft and Adobe designed the Open type language to support all the different writing styles around the world...For example for Farsi/Arabic, you can tell the font file when to substitute "ALEF / LAM / LAM / Ha" with the specifically designed "ALLAH" glyph...or even you can say where to place a "HAMZA" or "FATHA" on "ALEF" or "JIM" because their glyph heights are different and you need to tell where exactly you want your diacritics to be placed...
'Glyph Substitution' data is stored in separate table in your font file and all the substitution are done by Operating System Font Rendering Engine, while you're typing in compatible softwares on your computer...so don't think that Microsoft Word is replacing the glyphs!...it is the job of font engine and it uses the data you've stored in your font file!...So now we must know how to enter this data in our font file...
When you open an existing font (opentype), most probably it contains standard Glyph Substitution data and the only thing you need to do is to change the glyphs...but when you want to add a new substitution rule to the file, (fore example for substitution glyph for "KAF", "LAM", and "ALEF") you need to create this table yourself from scratch...
If you use advanced sofwares like FontLab, you can use it's feature to enter Opentype Language Commands and FontLab will compile it into binary data and store it in your font file...But you need to buy the software and also need to study it's help to see how to write the codes you want...
I used a free software which is capable of compiling all the Opentype codes into your font file...It is Microsoft VOLT and you can download it from microsoft website here...it also has a very comprehensive documentation on opentype features which you can read and use...well, I have to say it is not an easy software to use but I must say it worths learning it because it supports all the open type codes and tables you may want to create while other softwares may support only a few of them based on the language they've been designed for...
If you're using VOLT, first you need to finish placing glyphs in your font file, and delete all the extra glyphs you don't want to have like symbols and etc...then open your file in VOLT and step by step, start creating glyph groups, substitution rules, etc...Then compile the font and you're done!!
If you want the Microsoft windows to show the famous Opentype icon (the one with a big O) for your file, you must digitally sign it...
Here is the VOLT file I created for my font...open it in VOLT and see how it's done...