How to write a macro correctly which contains a 'char'?

[Stefan_Salewski]

There exists a few macro tutorials...

But as I am not really good with macros I would try something like
    
    
    let h =
      case l.ch
      of '+': tkPlus
      of '-': tkMinus
    ...
    tok = Token(h, Literal: $l.ch )
    
    
    Run

You may not even need a case statement, I think ascii characters are valid for 
array index, so you may use an array with tk*** content?