怎么在vb.net2005中，对数据集中的数据表的某行某列的值进行取出和修改
Dim myconn As New OleDbConnectionDim myda As New OleDbDataAdapter
myconn.ConnectionString = "provider=microsoft.jet.oledb.4.0;data source=db1.mdb"
Dim myda As New OleDbDataAdapter("select * from 商品数据库 ", myconn)
Dim mycmdbuilder = New OleDbCommandBuilder(myda)
myda.Fill(myds, "商品数据库")
Dim mydv As New DataView(myds.Tables("商品数据库"))
myconn.Open()
假设myds.Tables("商品数据库")表有n（n>=10）行，现在我想取出和改变第五行第五列的值该怎么做？越简单越好
