CCL: substructure searching for two smile strings

 Sent to CCL by: "Chunhui  Li" [lixxx667[A]]
 I have two smile strings and would like to know if the one is the other one's
 substructure. Could you please let me know what would be the best solution to
 this? any software available or I have to write my own code for this?
 thanks a lot,