negative numbers w/o negative sign

OK, im working on a school project and it is to make a checkbook register with the common credit and debit columns. We are given the values to enter and supposed to make the debit column show in parentheses and in red automatically, without entering a - in front of the entries. I cannot use the number dialog box as I dont have - in front, only tip teacher gave is use a formula at top of column.
example of debit entry 124.18, no - sign, no dollar sign.
please help, im going insane.
excel 2007

Hi,

Excel number format syntax is:

Positive Numbers ; Negative Numbers ; format for Zero values; format for text
--- Note the semi-colon, this separates the different formats for each value type---

So,
If you want to fomat negative numbers with parenthesis and coloured RED
Right click on a cell you want to format.

From the pop-up mouse menu select Format Cells.
On the "Numbers" tab select 'Custom'
On the righthand side of the of the tab you'll see a list of formats with one directly under the word 'Type:'

Click into this, highlight by dragging the mouse and type in for following.

#,###.#0;[RED](#,###.#0);-;

This will give you:
Positive Numbers with two decimal places and thousands separated with a comma
Negative numbers encapsulated in parenthesis and coloured RED, with two decimal places and thousands separated with a comma
Zero values will be shown with a dash (or minus sign) to show that the cell is not empty,

When you've time go to Excel Help and search for 'Custom Number Formats' - very useful.


Hope that helps