在命令窗口执行下面的代码，就能完全实现你的要求：

Dim nms1() As String = {"商品名称","规格","客户名称","出仓","业务日期"}
Dim nms2() As String = {"商品名称","规格","客户名称","出仓数量","出仓日期"}
Dim nms3() As String = {"商品名称","规格","客户名称","采购数量","业务日期"}
For Each dr1 As DataRow In DataTables("存货统计表").Select("过账 = False And 出仓 > 0 And 客户名称 Is Not Null")
   Dim dr2 As DataRow = DataTables("订单表").AddNew
    For i As Integer = 0 To nms1.Length -1
       dr2(nms2(i)) = dr1(nms1(i))
    Next
   dr1("过账") = True
Next
For Each dr1 As DataRow In DataTables("存货统计表").Select("过账 = False And 进仓 > 0 And 客户名称 Is Not Null")
   Dim dr2 As DataRow = DataTables("采购计划表").AddNew
    For i As Integer = 0 To nms1.Length -1
       dr2(nms3(i)) = dr1(nms1(i))
    Next
   dr1("过账") = True
Next

相关知识点：

http://www.foxtable.com/help/topics/1533.htm

多谢狐爸指点。