Hello,
I'm from france (sorry for my english) and new on this site.
After several hours of searching, I submit my question:

How to make a font with IME (Input Method Editor) ?

Let me explain:
1 - With some Chinese fonts for example, if you type eg "M" MSword processing offers a Chinese character.
If you type "Ma", we get a list of several homophones characters of "Ma" and you chose the right.
This is what we call an Input Method Editor. Here is a link where it is explained:
http://msdn.microsoft.com/en-us/library/aa292134%28v=vs.71%29.aspx#vxconlanguageissuesanchorinputmethodeditors

2 - (maybe should be a musician to understand) : I started to create a font that displays chord.
But with a classic font, 255 characters is not enough for all the chords. And then there are several ways to play the same chord.
(So, it wil be more than 500 characters in the font. I think I should use a 2-byte font or unicode ...)
Someone has already made a police few years ago but it's not easy to use and very incomplete : http://www.dafont.com/farhat.font?text=abcdefg


I would like : If I type (for example) "Cm" (a C minor chord), the IME displays 7 or 8 characters corresponding to the 7 or 8 ways to play a C minor and we'll just have to choose (as is done in Chinese).
Thus, the use of this policy would be easier than to get special characters (or ASCII) and I would not be limited to 255 chords which is not at all sufficient.

Specifically, it might be useful for some players like me, who want to write the lyrics of a song with the chord above without having to copy and paste images.
For example, type F and presto, it offers 8 ways to play an F, and chosen, for example between 8 :
http://guitare.lyon.free.fr/coursenligne/accords/accords-guitare-de-fa.jpg

So, I hope someone masters the input method editors. I spent lot of time to search, I don't know if anyone will be able to answer me because it doesn't look simple ... Perhaps, commercial software can to do that??
Thank you.

There are programs out that try to do exactly what you are talking about. The app I recently bought is called Songbook. It's a fairly poor attempt as far as a GUI and input method but the underlying format is a small set of HTML command structures that put chords above lyrics in "chord pro" file format and I think there is a way to define your own chord shapes. Here's a link http://webchord.sourceforge.net/ If you know of a basic ASCII text editor for android that will let me assign macros to virtual keys and view XML files, let me know.