Using LIKE '%variable%' with a parameterized query

I am trying to accomplish something like...

SELECT ItemID, ItemNumber, ItemDesc FROM ITEMS WHERE ItemDesc LIKE '%variable%'

The problem is I am using a parameterized query, so it is structure like...

rsItems_cmd.CommandText = "SELECT ItemID, ItemNumber, ItemDesc FROM ITEMS WHERE ItemDesc LIKE ?"

and then passing the parameter...

rsItems_cmd.Parameters.Append rsItems_cmd.CreateParameter("param1", 200, 1, 50, rsItems__Variable

(Where rsItems__Variable is a string of the value passed)

How do I use a LIKE command when passing a text string as a parameter??