Hi ParaToxic,
forget Blitz3D (LoadAnimTexture or so..) it just a tricky function/structure to hide the texture coordinate calculations.
You can load the texture above in a whole and then display a "frame" by setting the uv coordinates to
x1 = row / maximumRow;
y1 = col / maximumCol;
x2 = x1 + (1.0f / maximumRow);
y2 = y1 + (1.0f / maximumCol);
This is just one method, i bet there are plenty different. You just have to see the whole texture from 0,0 to 512,512 as 0,0 to 1,1 and then "scale" it to your needs.
E.g.:
If you have a 512x512 texture and want to show 0,0 to 256,256 then you have to write
x1 = 0
y1 = 0
x2 = 0.5
y2 = 0.5
ps. x1/y1 and x2/y2 are the uv coordinates if you see the texture as a simple rectangle (they are the corners).
Hope this helps you.