Sure, I can help you with that! In Excel 2007, you can use the "Edit Data" feature to achieve this. Here are the steps:

1. Select the line chart you want to edit.
2. Click on the "Design" tab in the ribbon.
3. Click on "Select Data" in the "Data" group.
4. In the "Select Data Source" dialog box, click on the "Edit" button under "Legend Entries (Series)".
5. In the "Edit Series" dialog box, click on the "Series Values" field.
6. Click on the cell that contains the data you want to edit.
7. Change the value in the cell to the desired value.
8. Click on the "OK" button to close the "Edit Series" dialog box.
9. Click on the "OK" button to close the "Select Data Source" dialog box.

Now, when you select a data point on the line chart and drag it up or down, it will change the data in the associated cell. This should work the same way as it did in Excel 2000.