#pas
var 
s1:string;
begin
s1:='Привет!';
SomeFunc(s1);
end;

#pas
unit HiAsmUnit;

interface

uses kol,Share,Debug,MyDLL,windows;

type
 THiAsmClass = class(TDebug)
   private

   public
   on_SomeFunc:THI_Event;
   procedure do_SomeFunc(var _Data:TData; Index:word);
   
 end;

implementation

procedure THiAsmClass.do_SomeFunc;
var 
s1:string;
begin
s1:='Привет!';
s1:= SomeFunc(s1);
_hi_onEvent(on_SomeFunc,s1)
end;

end.

#pas
library MyDll;

uses Windows;

function SomeFunc(I: string): string; stdcall;
begin
    Result := 'asd';
end;

exports
  SomeFunc;

begin
end.

#pas
var buf:string;
...
function ReceiveString(p:pchar):PChar; stdcall; export; 
begin
   buf := 'Receive text: ' + p + #0;
   Result := PChar(buf);
end;

#pas
var s:string;
...
s := ReceiveString('some text');
// use s here

#pas
unit FirstLib;

interface

uses Kol,Share,Win,Windows,Debug,Messages;

function ReceiveString(p:pchar):PChar; stdcall; export;
  
implementation 

var buf:string;

function ReceiveString(p:pchar):PChar; stdcall; export;
begin
   buf := 'Receive text: ' + p + #0;
   Result := PChar(buf);

end;
end.  

Add(MainForm,2953706,21,105)
{
}
Add(Button,8818931,168,119)
{
 Left=125
 Top=105
 Data=Integer(5)
 link(onClick,11718020:do_inputString,[])
}
Add(Label,1201926,287,119)
{
 Left=200
 Top=110
}
Add(InlineCode,11718020,224,119)
{
 WorkPoints=#14:do_inputString|
 EventPoints=#14:on_inputString|
 Code=#15:unit HiAsmUnit;|0:|9:interface|0:|38:uses kol,Share,Debug,FirstLib,windows;|0:|4:type|28: THiAsmClass = class(TDebug)|10:   private|0:|9:   public|28:   on_inputString:THI_Event;|57:   procedure do_inputString(var _Data:TData; Index:word);|3:   |5: end;|0:|14:implementation|0:|37:procedure THiAsmClass.do_inputString;|13:var s:string;|5:begin|33:s := ReceiveString('Мой текст!');|13:// use s here|29:_hi_onEvent(on_inputString,s)|4:end;|0:|4:end.|
 link(on_inputString,1201926:doText,[])
}

library MyDll;

uses Windows;

var buf:string;

function ReceiveString(p:pchar):PChar; stdcall;
begin
   buf := 'Receive text: ' + p + #0;
   Result := PChar(buf);
end;

exports
  ReceiveString;

begin
end.