How to change raw char string to 16-bit 2's complement integer?

Hi,

Please see the following raw char sting

óèóóóóþþóèþóóóþóþóóèþóóóóóóóóóþóóóóóèóóóóóþóóþþóóóþóèóóþóèþóèóþóóþóóèþóóóþèóóþóþóþóóóþóóóþóèóþþèþóþó

How could I converter it to 16-bit short signed integer 2's complement?

Thanks,

Ott