Via GDI/GDI+ get the text pixels or glyph, how to convert to 3d mesh? Does any exists library or source code can be used?

PS: I know D3DXCreateText, but Im using opengl...
['https://Stackoverflow.com/questions/18042485', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/1716020/']
If you works on OpenGL, you can try FTGL, it allows you to generate different polygon meshes from fonts, including extrudes meshes as well as render them:

<http://ftgl.sourceforge.net/docs/html/ftgl-tutorial.html>

but I am not sure how portable is this library specially for OpenGL ES...
Using GDI is definitely not among the best ways to go if you need to obtain glyphs for the text, you could use FreeType library instead (<http://www.freetype.org>), which is open-source and portable. It can produce both bitmaps and vectorized representation for the glyphs. You will have to initialize single instance of class FT\_Library in your program that is later used to work with multiple fonts. After loading font form file (TrueType, OpenType, PostScript and some other formats) you'll be able to obtain geometrical parameters of specific characters and use it appropriately to create texture or build primitives using your preferred rendering API, OpenGL let it be.