Serial communication RF protocol

I have a system with one arduino master connected to the PC and slaves(others arduinos).Each have a RF 434Mhz receiver and transmitter.
I use the virtualwire library to communicate between master and slave.
I control slaves arduinos by input a sequence of numbers(protocol),for example:
start character+sum+information(control sequence)+end character

Information(control sequence)=ID slave+action to make+information pin arduino to do this action.
This information i input over serial port(example 03+1+01,sequence "03101"5positions)and put it to the send buffer(array,0 number to position 0 and 3 to position 2).
I use the ASCII code 1 to 9 because i think is better to put it on the send array but if i use binary have 0-255.
If i use binary code i have 0-255(example 0-255IDs+0-255actions+0-255information pin=3positions) and not 1-9 and use less buffer positions to make the protocol but the problem is who a input the sequence over serial port(see my example sequence)if i use de second example.
Any idea?