I have a list view that calls a store for the list data. I am trying to pass data to the store for filtering or a different url for the proxy how would I accomplish this?

List View:
Code:
Ext.define('MonkTouch.view.List', {
    extend : 'Ext.List',
    xtype  : 'mtouch-list',
    
    storeId:null,
    constructor : function(config) {
        this.setItemTpl(config.template);
        Ext.apply(config, {
            store : Ext.create('MonkTouch.store.Media')         
        });
        this.callParent([config]);
    }
});
Store:
Code:
Ext.define('MonkTouch.store.Media',{
    extend: 'Ext.data.Store',
    model: 'MonkTouch.model.Media',
    
    autoLoad: true,
    proxy:{
        type:'ajax',
        url:'/lib/mk-modules/media.php',
        reader:{
            type:'json',
            root:'items'
        }
    },
    remoteFilter:true,
    filters:[]
});