So Freesco does have this DNS ?
Here isn't the place to ask about Freesco.
If you've registered a domain, you should know (or be able to find out) where the domain's DNS servers are located. Your domain registrar should be able to publish DNS for you if it's not currently being published (or is currently, but your freesco). If not, there are other free services (although possibly not in the .lv domain).
If you DNS is published externally, then you need to either configure your SME server to match the address it already publishes, or you need to configure dynamic DNS in the console so that the externally published DNS is updated when your Internet address changes.
Have you read the user guide?