Is this a correct way of doing an optimistic update

Imagine two different users executing this code at the same time.
I can not use the CRecordset Update Delete methods for this.

// Check to see if version number has been incremented since this view read in
// the client data

    CClientRecordSet rs(mConn);

    rs.m_strFilter = "ID = ";
    rs.m_strFilter += client->GetKey();
    rs.m_strFilter +=" AND ";
    rs.m_strFilter += "Version = ";
    rs.m_strFilter += client->GetVersion();

    // Assuming here, this is acting as a lock on tables referenced
    mConn->BeginTrans();
    rs.Open(CRecordset::snapshot, NULL, CRecordset::readOnly);

// No record match so version number incremented, some else has edited the
// record or it has now been deleted.

    if(rs.IsBOF()){
        throw new AppException("Client view is stale (Phantom
                                                                      read),
refresh view");
    }

// else ok to edit, plus record/ table locked while update prepared
    CString sql("UPDATE Client SET Name='");
    sql += client->GetName());
    sql += " Version = ";
    sql += client->GetVersion() + 1;
    sql += (" WHERE (ID = ");
    sql += client->GetKey();
    sql += ')';

    mConn->ExecuteSQL(sql);

// release lock
    mConn->CommitTrans();

    client->IncrVersion();

So given select was successful, will this record be locked due to the
transaction?
How can i lock the appropriate record outside of using CRecordset update etc?

Thanks.