Pointer the open array

How would i have a parameter for a procedure thats a pointer to an open
array,
i've tried:

Type
 TChArray = Array of Char;

procedure ArrayProc(ChArray : ^TChArray);
begin
 {stuff}
end;

but you can't have an open array outside the procedure's parameters..
ive also tried:

procedure ArrayProc(ChArray : ^Array of Char);
begin
 {stuff}
end;

but you cant set pointer to an array w/o setting it as a type first
(unless i dont know how)

Can anyone help me out? Please, any help is appreciated.
Thanks much-