Here is Gord Dibben's reply to a similar post:
Select the range.
Data>Text to Columns>Next>Next>Advanced. Checkmark in "trailing minus sign for
negative numbers">Finish. (This feature appeared with Excel 2002)
A macro if you wish.
Sub Negsignleft()
Dim cell As Range
Dim rng As Range
''move minus sign from right to left on entire worksheet
On Error Resume Next
Set rng = ActiveSheet.Cells. _
SpecialCells(xlCellTypeConstants, xlTextValues)
On Error GoTo 0
For Each cell In rng
If IsNumeric(cell.Value) Then
cell.Value = CDbl(cell.Value)
End If
Next cell
End Sub
Put the macro code in a general VBA module in your workbook. If you are new
to macros, this link to Jon Peltier's site may be helpful:
http://peltiertech.com/WordPress/2008/03/09/how-to-use-someone-elses-macro/
Hope this helps,
Hutch