playing with numbers

again, I'm swimming ...
objectives : display the ADC (10 bits) values in an OSD (On Screen Display)
module.
détails : ADC values (0 to 360) are ok (test made using serout #adval)
OSD module is waiting for command like
define ligne and position (OK)
define type of character (OK)
enter value 1 and value 2 and finally value 3 (in my case !)
to display a "1" it is value 1 ,for a "2" it is 2 and so on (i'm lucky !)
Question 1 :
assuming ADVAL (word) is 321 (in decimal) , what is the good PBP routine to get 3 and 2 and 1 ...
Already I have a routine to know if the value is less than 9 or 99 or more
to know the value size ! 1,2 or 3 characters long
I try to "play" with DEC command as described in Serout2 help pages, but
without success (by the way, is there some example to better understand
the following lines)
Modifier Operation

{I}{S}BIN{1..16} Send binary digits

{I}{S}DEC{1..5} Send decimal digits

{I}{S}HEX{1..4} Send hexadecimal digits

REP c\n Send character c repeated n times

STR ArrayVar{\n} Send string of n characters

thanks in advance for your help
Francois