_userTable = ((SAPbobsCOM.Company)sboApplication.Company.GetDICompany()).UserTables.Item(_tableName);

_userTable.UserFields.Fields.Item("U_" + fieldName1).Value = value1;
_userTable.UserFields.Fields.Item("U_" + fieldName2).Value = value2;
_userTable.UserFields.Fields.Item("U_" + fieldName3).Value = value3;

_userTable.Add();