I suspect you have more information than just a last name and a town. Such things as which members (first names) of the Sobolevitch family came from Vilkavis^kis.
Do you have approximate/exact dates of birth and other info? Where did they emigrate to (America, Canada, Australia)? If to America, where did they live (city, neighborhod, street address)? When did they emigrate (before WW I, DPs after WW II) from which port and where did they land?
The more details you can provide, the higher the chances that someone will be able to add to your store of knowledge regarding the family history.