How Do I Pass A Paramater?

Hey everyone I'm having trouble finding a way to pass a particular paramater, my main goal of this is to create a custom paging and sorting control for the DataList, but we wont worry about all the un-nessesarry code, here is what I am dealing with... Sub Page_Load()

Dim Conn As SqlConnection
Dim Query As String
Dim SqlComm As SqlCommand
Dim myDataReader As SqlDataReader

' Define connection object
Conn = New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)

' Define query to retrieve main category values
Query = "SELECT [productMainCategory] FROM [User_Products] WHERE [productMainCategory] = @productMainCategory"
' Define command object
SqlComm = New SqlCommand(Query, Conn)

' Open connection to database
Conn.Open()

' Create DataReader
myDataReader = SqlComm.ExecuteReader()

' Iterate through records and add to array list
While myDataReader.Read()
IDList.Add(myDataReader("productMainCategory"))
End While

' Close DataReader and connection objects
myDataReader.Close()
myDataReader = Nothing
Conn.Close()
Conn = Nothing

' If page has not been posted back, retrieve first page of records
If Not Page.IsPostBack Then
Paging()
End If

End Sub

The Entire Point to this bit of code is to open a connection to the database find the category productsMainCategory, count all the fields with the Name 3D Art --> and save that number into an Array List where I will be using it later on in my code......The big old problem here is that it counts every single field in the productsMainCategory, Columb.........I need to figure out how to pass it a parameter so that it only counts my 3D Art --> fields, I have tried using this bit of code but nothing             SqlComm.Parameters("@productMainCategory").Value = "3D Art -->"
Does anyone have any ideas of how I might go about donig this?
Thank You..