To remove the leading 1 from a nine digit telephone number stored in a column in Excel, you can use the following formula:

=RIGHT(A1,10)

Assuming that your telephone numbers are stored in column A, this formula will take the last 10 characters from the right of the cell, effectively removing the leading 1.

Here's how to use this formula:

1. Insert a new column next to the column containing the telephone numbers.
2. In the first cell of the new column, enter the formula =RIGHT(A1,10), assuming that your telephone numbers are stored in column A.
3. Copy the formula down to the rest of the cells in the new column.
4. The new column will now contain the telephone numbers without the leading 1.

Alternatively, you can also use the Find and Replace feature in Excel to remove the leading 1 from your telephone numbers. Here's how:

1. Select the column containing the telephone numbers.
2. Press Ctrl+H to open the Find and Replace dialog box.
3. In the Find what field, enter "1" (without the quotes).
4. Leave the Replace with field blank.
5. Click on the Replace All button.
6. Excel will replace all instances of "1" with a blank space, effectively removing the leading 1 from your telephone numbers.