Converting from String^ to BSTR

//
        // Converting from String^ to BSTR
        //
        pin_ptr<const wchar_t> wch = PtrToStringChars(domainControllerName);
        domainControllerNameToPass = ::SysAllocString(wch);

        wch = PtrToStringChars(distinguishedName);
        distinguishedNameToPass = ::SysAllocString(wch);

        wch = PtrToStringChars(verifyNameDomainControllerName);
        verifyNameDomainControllerNameToPass = ::SysAllocString(wch);