Bits 15,14,13 show a status of the AntiLag. ...there can be up to 7 states a feature is in.
what can I use to combine these 3 bits and give me the decimal?
STATUS2 will be a byte and you can construct it like this
STATUS2 = bitRead(STATUS1, 15) <<2 + bitRead(STATUS1, 14) <<1 + bitRead(STATUS1, 13);
Using the power of 2 multiplication equivalent to the bitshifts the combined value can also be written
STATUS2 = bitRead(STATUS1, 15) *4 + bitRead(STATUS1, 14) *2 + bitRead(STATUS1, 13);
The compiler treats them the same, so you can use whatever you understand the best.