Collision Question

I am makeing a simple OpenGL game where the window will be like for example 10 X 10 (though you wouldnt want it this small) and have blocks arounf the whole perimeter and have a block the same iz in the middle moving in random directions. I am gonna have a function that makes the mov_block and perim_block, and have to different squares the same size for collision tes and make it invisible but it tranparent. If the move_block hits a perim_block it will start to move in the opposite direction. i was wondering how can I make it so every time I call the function to place another perim_block around the window, it places the collision block in the same position so i dont have to do it every time? Thanks!!!!! ~Mad_Kod3r~