Tables(str1).Current("产品编号")
或者
Dim str1 As String
If e.Selected Then '如果选择了值
Dim tbl As Table = Tables("采购计划简称筛选录入窗口_Table1")
If tbl.Current IsNot Nothing Then
e.Form.DropDownBox.Value = tbl.Current("简称")
If e.Form.DropTable IsNot Nothing Then
e.Form.DropTable.Current("产品编号") = tbl.Current("产品编号")
End If