only few record to be order by RAND() in mysql-php code rest of records to show as it is in bottom

I am stuck in a very simple thing and i am not able to get through. please help I have a table of 500 records and use to display 100 record per page on my html webpage. I want first 100 records (or any specifically selected 100 records) to be always shown with ORDER BY RAND() and the rest of 400 records display in the order as they are in the table.

To elaborate more - I need help in mysql_query which returns first 100 records Order by RAND() always but the rest of record should return as it is in the table. There should always be those selected 100 records and those too should return in random on first 100 positions always but in random order. please help me I will highly obliged. Thanks in advance