Well I've made you a little something, it might be useful for you.
Usage: $plot(string,N,char)
The N stands for the amount of first characters you want to be visible from each word.
Examples:
$plot(this is a test,0,*) -> **** ** * ****
$plot(this is a test,1,*) -> t*** i* a t***
$plot(this is a test,2,*) -> th** is a te**
$plot(this is a test,3,*) -> thi* is a tes*
...
alias plot {
var %a, %b = $regsub($1,/(?<=\S{ $+ $2})\S/g,$replace($$3,\,\\,$,\$),%a)
return %a
}