Lets use your example
Hex: 00 00 00 03 00 00 1c 5a 00 00 00 18 03
Decimal: 0 0 0 3 0 0 28 90 0 0 0 24 3

Open excel
put 90 in N15
put 28 in O15

put in cell N17 =DEC2BIN(N15,8)
put in cell O17 =DEC2BIN(O15)
put in cell P17 =O17&N17

put in cell N19 =BIN2DEC(VALUE(RIGHT(N17,5)))
put in cell O19 =BIN2DEC(VALUE(LEFT(P17,8)))

this is how you get 26.226 from the above
24 is the command function

Sony generally have been using the following to indicate the command length
01 = Sony 12
02 = Sony 15
03 = Sony 20

I can only guess thats the reason for the 03 in the string

Thats a start, will look into it a bit more tomorrow