LuaLatex , how put glyph freely

Lua are incredible engine. I have a font in ttf and I would put a specific glyph in a specific place.
For example I create a logo.

I need to put second version of ‘a’ in (x,y)=(12pt,30pt) from left upper corner.
Next put ‘失’ in 2pt to the right of previous glyph. First glyph are 11.234567pt height second 9.73pt height. Not changing a main font because each glyph will be from different font.

I need:

• set font name
• set height
• width of glyph (meybe with kerning)
• create a page
• put a glyph to the page (I have a number in unicode or other way)

I’m using tex only as engine to create a pdf , everything else I can create himself. Meybe using tikz?