command.com echo command

you still missunderstand ... from his specs it seems like he wants to do his own console.
That actually would be fairly simple given the fact that you have some kind of fixed command structure.

Given you have your input stored in cmd:string, then you could simply do

 local cmdCall:string = cmd.split(" ")
 local cmdData:string = right( cmd, cmd.length - instr(cmd, " ")+1))
 select cmdCall
  case "echo"
   print cmdData
 end select