There is none, and I won't call it "tokens"
But I hope that's what you want:
alias insert {
var %d = $chr($$2)
return $regsubex($1,/(?<=\S)(\S)/g,%d $+ \1))
}
//var %text = This is a test message | echo -a $insert(%text,42)
returns:
T*h*i*s i*s a t*e*s*t m*e*s*s*a*g*e
(Note that "asterisk" has ascii value 42, not 44)