printf and unsecable char

Hello I would like to print a string formatted on the right side and fill in the left side with the unsecable character [ ] I read in the printf command I could use : printf( "%#30s" , $mystring ) ; to display $mystring string with the character # before (on the left) and I try to replace # by   but I can't find a solution

Do you know the solution to write the command:          printf( "% 30s" , $mystring ) ;

or something like that ! Best regards and take care ! -- Jean-Philippe Battu http://jeanpba.homeip.net