Flip sign in complex expression

[Rob]

Hi all, 

is there a way a flip sign can be applied to a mask account mapping that contains a complex expression? See screenshot below (partly), the customer created nearly 4000 lines of code in here. 

[chul]

This would be better handled by out-of-the-box functionality with the flip sign box rather than using the complex expression. The admin could put this into an excel or TRX file and upload it rather than building it directly in the transformation rule interface. It would also ease maintenance going forward as the admin wouldn't need to modify the CE.