hex -> 16bit signed int (newbie)

[zif]

How can I get 16bit signed int from a hex string?
Eval('0x...') gives me 16bit unsigned,
struct.pack('i', '\x..\x..') works fine, but
Python doesn't allow me to concatenate strings
with '\' (str(92) gives me '\\', which doesn't
work as well).

Thanks.