For this to have happened, the contents  are numeric.
If you're wanting the "()" to show, you have two choices.
change the formatting of the cells to use () for negative  numbers:
"0.00_);(0.00)"
or change it to a text string.
which will cause you problems if you're trying to use add  the numbers.
If you're wanting to change the contents to text (to essentially
remove them from the calculations) use:

ActiveCell.Offset(1, 0).Value = "'(" & ActiveCell.Offset(1, 0).Value
& ")"
(note added single quote)