1。找到元素坐标；
HtmlElement  OffsetRectangle.X,Y属性可以知道坐标
2。C#控制鼠标移动
通过SetCursorPos(x,y)可以控制鼠标坐标

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;namespace WindowsApplication10
{
    public partial class Form1 : Form
    {
        [DllImport("user32.dll")]
        private static extern int SetCursorPos(int x, int y);       
        public Form1()
        {
            InitializeComponent();
        }
        int i = 0;       
        private void Form1_Load(object sender, EventArgs e)
        {
            timer1.Interval = 10000;       
        }       
        private void timer1_Tick(object sender, EventArgs e)
        {
            i = i + 3;
            SetCursorPos(i, i);
        }
    }
}