Alligning to grid?

I am making this little demo that has a grid (directx application) of lines 32x32. There is this box, 32x32, which has to move randomly in the grid, alligned to it. What I do is performing a rand()%viewport.Width and Height for the x,y of the box (x,y is the position of the top-left corner of the box). The problem is, that I cant make rand() work only for randomizing values multipliers of 2, which is 32 i want. ANy ideas?
I hope you understand the question well,
Thanks!

Hmm, I didn't really understand, but this is the way to create a random number that is a multiplier of 2:

Code:

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int num = 2*(rand()%16);

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Thats is exactly what i wanted, thanks a lot!!