I want to be able to keep track of hours in Excel 2003.  So I would
have multiple rows where column 2 would subtract column 1 to give a
total time in column 3.

ie.  16:00  23:30  7:50

Then all column 3's would be added up to give a total time.  Example

16:00  23:30  07:50
01:00  06:00  05:00
10:00  14:45  04:45
12:00  13:00  01:00
              18:15

The problem I've run into is clock-rollover (after the total time
elapsed has hit 24 hours it reverts back to zero).

Thanks in advance!

Convert it to minutes

				=HOUR(G3)	=minute(g3)	7*60	30 + 420 total mins.	
16:00	23:30	7:30		7	30	420	450	
1:00	6:00	5:00		5	0	300	300	
10:00	14:45	4:45		4	45	240	285	
12:00	13:00	1:00	18:15	1	0	60	60	
16:00	23:30	7:30		7	30	420	450	
1:00	6:00	5:00		5	0	300	300	
10:00	14:45	4:45		4	45	240	285	
12:00	13:00	1:00	18:15	1	0	60	60	
		12:30	12:30			Total:	2190	
								
						Total hours	36.5	
								
						=ROUNDDOWN	36	
								
						1/2 hour	0.5	
								
						Convert to minutes	30

I want to keep the hour format.  This is a daily work log so that
reflects the start and stop time for tasks.  The third column needs to
be a time track that totals the difference between columns one and two
so it needs to be in 00:00 format as well.

I did this in Office 2002.  It may be diff in 2003.

Highlight all the cells.  Format cells (control + 1).  Go to the
number tab.  Select the time category.  Pick the 7th type (shown as
37:30:55 [could be different in Off 2003]).

HTH

That's the way I have it.  The problem is it rolls over the time once
the total reaches 24 hours.

See this screenshot for an example.

http://www.xorply.com/xclscreenshot.jpg

I suggested to convert it to minutes.  Just convert back into the format you'd like.

The suggestion from james_l_mar-ga to format the cells worked for me
in Office 2003 using the numbers from your screenshot.

Looking closer at your example screenshot, it looks like cells E2
through E22 are formated as james_l_mar-ga suggested.  However, the
cell that matters, E23, appears to be formatted differently.

The only difference I see between the example you gave when you posted
your question and the solution from james_l_mar-ga is that your
example displays the total as hours and minutes while his solution
displays it as hours, minutes, and seconds.

If you want to avoid both clock-rollover and the display of the
seconds, you can set the cell to a custom format of [h]:mm

(Note: The brackets around the "h" are necessary.)