How do i load and use a semi-transparent bitmap?, i could not find the answer on the forum so instead i'm making a new thread on the subject.

^^'.. i know that much.. i meant:
how (if it's possible) can i draw some sort of image that's not 100% transparent(parts of it).

I guess i didn't give such an good explanation..
I want to load a picture where some pixels are transparent and others are not.
i don't want the whole picture drawn with the same transparency.

I'm wondering if this is possible.

I've added an attachment, it's an example of what i'm trying to do, where the chess-board-look-alike background is the transparency, of course the bitmap can't be used but i'm wondering if this effect is possible with allegro and if so in what kind of format should the image be stored?.

set_color_conversion(COLORCONV_NONE);
BITMAP *bmp = load_tga(path, NULL);

I thank thee, .