RE: import opportunity from excel

if you want to write code for this, you can try you logic as under

DirOrganization                     dirOrganisation;
DirParty                            dirParty;
;

dirOrganisation.Name                    = "Name"
dirOrganisation.NameAlias               = "SearchName";
dirOrganisation.LanguageId              = stemParameters::getSystemLanguageId();
dirOrganisation.KnownAs                 = "Name"
dirOrganisation.PhoneticName            = "AnyName"
dirOrganisation.insert();

dirParty                                = new DirParty(dirOrganisation);
smmOpportunityTable.Party             = dirPerson.RecId;