There seems to be no such function, but it is not difficult to write one yourself. You can use this function directly in the following sample program:

{$apptype console $}

Function nstr0(x, n: integer): string; //Call example writeln (nstr0 (123,5); Output 00 123

Var i: integer;

begin

Setlength (result, n);

for i:=n downto 1 do

begin

result[I]:= chr(ord(' 0 ')+x mod 10)；

x:= x div 10；

End;

End;

begin

write(nstr0( 123，5))；

End.