Balance sheet number formatting

Hello,

I have a tablet that show the balance sheet of a company, where revenue and expenses are shown, to calculate profit or loss.

The client needs this specific requirments of having all the expenses shown as numbers between brackets (###,###.##)

Any idea how I can achieve this.

I tried having a calculating column where I can enter the type of the item in the balance sheet (expense or revenue).

But I am stuck of having the conditional formatting works as a condition of different column.

Please help