about coordinate of lone pair electron

[student <chenhua[ AT ]ms.dicp.ac.cn>]

Dear netter:
 i am sorry for ask this question again,because i has not got answer from anyone
 as now.
 my question is that :
 Are there web page or free software for automatically adding coordination of
 lone pair electron of O,N,P,S from file in which
 there are only coordinations of atoms in CCL.
 thanks in advance!!!!