How to pass a text comma-separated parameter into SSRS sql query

Hi, two questions:

1-  I have text string parameter @myParm that can have values like '10,20,22'.  In SSRS I want to use statement like Select fname, lname from employee where id in (@myParm).  This will not work unless I have a multi select parameter.  I am not using sql stored procedur.

2- Can I create a hidden multi select parameter and feed the values of @myParm into it and use that inside my query?

thank you.