How to use replace in a expression

[ivanville18]

Hello, please help me! I have this expression: 

=Count({<Message={'Activated sheet Document\SH01','Activated sheet Document\SH02','Activated sheet Document\SH09','Activated sheet Document\SH10','Activated sheet Document\SH11','Activated sheet Document\SH12','Activated sheet SH01','Activated sheet SH02','Activated sheet SH09','Activated sheet SH10','Activated sheet SH11','Activated sheet SH12'}>}Message)

I need to replace the text in the table : 'Activated sheet Document\SH01' and 'Activated sheet SH01' for the text 'Inicio', and the same for the other values for example: 

Activated sheet Document\SH02' and Activated sheet SH02 for the the text 'Billings'

Do  I need to modify the expression or I need to do in the script? 

Thanks!

[anushree1]

Either Way it should work , If you are changing the Script then the column names will be renamed;

If on Expression it will be the correction done to match the applicable values.

[ivanville18]

Thank you so much, you know how to modify the expression?