How to get the SID of the group and the size of the buffer in which it is written?

You need to get the Sid of the group, not the user ... By the example of the function

BOOL WINAPI LookupAccountName( LPCTSTR lpSystemName, LPCTSTR lpAccountName, PSID Sid, LPDWORD cbSid, LPTSTR ReferencedDomainName, LPDWORD cchReferencedDomainName, PSID_NAME_USE peUse ); 

This function allows you to get the SID of the user, but not the group ... Maybe someone faced the same problem and knows the solution ... Please help ..