(not?) using preservingMatrix

In C OpenGL, you can do something like this to use matrices for computation without affecting context:

glMatrixMode (GL_MODELVIEW) ;
glPushMatrix () ;
glLoadMatrix (your_matrix) ;
// do whatever you want with your your matrix
// for exampl glMultMatrix (your_matrix2) ;
...
// at the end of your calculations use
glGetFloatv (GL_MODELVIEW_MATRIX, your_matrix_result) ;
glPopMatrix () ; // nothing has changed !!!

I'm not exactly sure how this is done with HOpenGL. i.e., how can I get the result of a matrix transformation not effecting the MODELVIEW, etc. matrices?  Could someone give an example?


Thanks,

Jamin