Passing comma delimited parameter to SP

Is this possible? I find it hard to believe that this could be sooo difficult. I have a simple select stored procedure that has one parameter. My application is passing a comma delimited string of values to be used in the IN clause.

Ex: Where x In(@.parametername)

the x column is an integer. How can one work around this?

Thanks!

http://www.sommarskog.se/arrays-in-sql.html