I have imported data into Excel 97 and negative numbers appear in columns
like this:

123.45-
24.21-
1000.78-

These are text and will not allow any sums. How can I convert the above to
numeric values so they appear as follows:
-123.45
-24.21
-1000.78

OR

(123.45)
(24.21)
(1000.78)

Thanks,