Bit Stuffing

I have three numbers that I'm limiting to 10 bits each and then hoping to packing into a 32-bit standard int.  This would be easy if the numbers were just positive, but they also could be negative.  I end up fighting with the 2s complement.  I know someone is going to suggest just saving myself some headache and forcing the last bit to represent a truncated positive/negative flag, but I really need all ten of those bits for the number (anyone have a 33-bit data type they can spare?).

Now I've already looked online and there isn't much to digest about the matter.  Of the two lonely solutions I've found, one doesn't seem to work and the other is a hassle to implement.  Knowing what I do about 2s complement I'm inclined to believe the latter is the case - it's a hassle no matter what - but I'm also stubborn enough to be believe that there is a more elegant solution.

>>11
You can't fit more than 32 bits of entropy in a 32-bit word. You cannot fit three times 11 bits of entropy (1 bit sign, 10 bits mantissa 0..1023) as that would amount to 33 bits of entropy, which is larger than the word size in this case. The best you can do is 10 bits of entropy (1 bit sign, 9 bits mantissa 0..511). And yes, you should use two's complement.