Yes, there is a quick way to insert a pound sign in front of multiple values in Excel 2003 without deleting the existing values in each cell. Here are the steps:

1. Select the cells that you want to add the pound sign to.
2. Right-click on the selected cells and choose "Format Cells" from the context menu.
3. In the "Format Cells" dialog box, select the "Custom" category.
4. In the "Type" field, enter the following format code:
   Code:

   "£0.00;-£0.00"

5. Click "OK" to close the dialog box.

Now, all the selected cells will display the pound sign in front of their existing values. If you want to apply this format to other cells in the worksheet, you can use the "Format Painter" tool to copy the format from the selected cells and apply it to other cells.

To use the "Format Painter" tool, follow these steps:

1. Select the cells that have the desired format.
2. Click on the "Format Painter" button in the "Clipboard" group on the "Home" tab.
3. Click and drag over the cells that you want to apply the format to.

This will copy the format from the selected cells and apply it to the new cells.