The technical documentation for the Latin Modern font family lists all available glyphs. There are more glyphs than are gathered in the accompanying encoding tables (CS, T1, L7X, OT1, OT4, QX, T5, LY1, TS1). I need glyphs like h with stroke or vowels with double grave accent. They are not in the encoding tables mentioned above. I cannot use Xe(La)TeX. My question is: How can I create new encoding table with needed glyphs?
Building a new font encoding similar to T1, QX or the others you're listing is not a trivial task.
The easiest part is to build the font table; the usual requirement is that printable ASCII character should stay in their place and that lowercase and uppercase versions of the same character are 32 places apart.
Next all non ASCII characters should be named; when applicable, the name is usually
Let's say your new encoding is
Now the hard part. You have to build each font you plan to use. There are tools around and also some papers on TUGboat.
A long term project, I'd say.
For limited needs, one can get away in an easier way, via composite glyphs. This has the disadvantage that hyphenation won't work past a composite glyph in a word, but you'll have hyphenation problems anyway if you don't want to also build the hyphenation patterns for the language you're writing in.
For instance, you can get double grave accents and LATIN SMALL LETTER H WITH STROKE with
As you see, the output is identical.
I don't know what you need to do to create new fonts. But to get the glyphs you need, you also don't need to. Just use the T3 encoding.