externalize the the field of xml element with white spaces

Hello Experts,

I need to externalize one of the XML elements with white space so that after transport I can update its value.

below is the sample XML, I need to externalize element "A".

length of this element "A" is 18

<?xml version='1.0' encoding='UTF-8'?>
<Root>
  <A>0000777799        </A>
</Root>

I tried with content modifier but it discards the white spaces.

Kindly help me with the solution for this.

Thanks,

Ravi