thanks for the fast reply,
i plan to rotate bones of a model and have this 3x3 rotation matrixes as source for the 3D rotations. now i have to move the bones according to the data in the matrix but have no idea how to do it.

i still have dificulties to understand ur answer. can u give me an working example code, for the following scenarios:

Matrix:

xx xz xy 0
zx zy zz 0
yx yy yz 0
0 0 0 1

is it DirectX-style?

0 0 1 0
1 0 0 0
0 1 0 0
0 0 0 1

1) now how to use the ang_for_matrix function to get the angles?

2) is it also possible to use the matrix above directly for rotation of my models bones?

thanks in advance