Ok, after some more research, i found out my main problem in not finding answers to my problem was the terms of research i was using. I was erroneously looking for "AS3 string replace with images" or "text replace with images in Flash", while the correct question was: "how to use a BITMAP FONT in AS3". I was sure someone else had to do what i'm trying to do (like in old games where texts were all image sprites) but i didn't know how to find it!
So, this is the solution i found, i still have to refine the workflow but it's a good starting point:
- Create a custom Bitmamp font using the SHOEBOX tool in conjunction with photoshop, where you will be able to apply all the raster fx you want (here's the tutorial: http://renderhjs.net/shoebox/bitmapFont.htm)
- You will obtain a .fnt file (descriptor) and a .png image (font characters atlas)
- You will need to flip the png image vertically: apparently, a lot of bitmap text engines work with flipped characters, and i found this one to be working like this as well
- Once you have these files, use the BMFontRenderer AS3 class to embed your bitmap font into an AS3 project of your choice (tutorial here: http://blog.bengarney.com/2011/12/07/fast-bitmap-fonts-in-flash/)
I hope it will be useful for others who may need to replace standard text in Flash with font images.