The IStringList::get_Item method retrieves an individual item from a string list.
HRESULT get_Item(
VARIANT Var, //VARIANT that contains the name of the item in the
// collection
VARIANT * pVariantReturn
//pointer to a VARIANT that receives the item value
);
You can use this method to retrieve a particular item from an array that has been returned by a Form, QueryString, or ServerVariables collection.
QueryString, Form, ServerVariables