界面放上一个DateTimePicker1，想按照日期分组统计

Dim g As New CrossTableBuilder("统计表2", DataTables("crm_sale"), "[sell_date] >= \'2013-1-1\'")
g.HGroups.AddDef("sell_date", DateGroupEnum.Year, "年")
g.HGroups.AddDef("sell_date", "月")
g.HGroups.AddDef("sell_date", DateGroupEnum.Week, "周")
g.VGroups.AddDef("seller")
g.Totals.AddDef("totalMoney", "totalMoney")
g.OrderByTotal = True
g.HorizontalTotal = True
g.VerticalTotal = True
g.Filter = "[sell_date]>=#" & e.form.Controls("DateTimePicker1") & "#"

g.Subtotal = True
g.FromServer = True
g.Build()
MainTable = Tables("统计表2")

g.Filter = "[sell_date]>=#" & e.form.Controls("DateTimePicker1") & "#" 这个是我自己填写的，运行提示“没有为字符串"[sell_date]>=# 和类型DateTimePicker定义运算符 ”&“在，这个错误，该怎么处理呀？