procedure my_insert(source:string;s:string;index:integer);
var
   s_t:string;
   i,j,count:byte;
begin
   for i:=1 to length(source) do 
   s:=s+' ';
   count:=0;
   for i:=1 to length(source) do
   begin
      for i:=(length(s)+count) downto (index+count) do
      begin
         s[i+1]:=s[i];
         s[i]:=' ';
      end;
      inc(count);
   end;

   for j:=1 to length(source) do
   for i:=index to (index+length(source)) do
   s[i]:=source[j];
   s1:=s;
end;

uses crt;

procedure my_insert(var source : string; subS : string; start : byte);
var
   T1,T2 : string;
begin
   T1 := copy(source,1,start-1);
   T2 := copy(source,start,255);
   source := ConCat(T1, subS, T2);
end;

var
   s,sb : string;
begin
   clrscr;
   s := '12345';
   sb := '00';
   my_insert(s, sb, 3);
   writeln(s);
   readln;
end.

procedure my_insert(var source : string; subS : string; start : byte);
begin
   source := Copy(source, 1, start-1) + subS + copy(source, start, 255);
end;

 uses crt;

procedure my_insert(var source : string; subS : string; start : byte);
var
   T : string;
   i    : byte;
begin

   T := '';

   for i := 1 to start - 1 do T := T + source[i];

   for i := 1 to length(subS) do T := T + subs[i];

   for i := start  to length(source) do
    T := T + source[i];

   source := T;

end;

var
   s,sb : string;
begin
   clrscr;
   s := '12345';
   sb := '00';
   my_insert(s, sb, 1);
   writeln(s);
   readln;
end.

   s := '12345';
   sb := '00';
   insert(s, sb, 40);