This solution requires jquery:
$("div[translate='MESSAGE_TOOLS_BILLING_CODE_REQ']")
This likely won't work in practice as I imagine MESSAGE_TOOLS_BILLING_CODE_REQ prints to yes/no (see documentation on translate paramter). The following lines would work in that case but this will not be very specific and you will likely have similar selection issues to currently.
$("div[translate='no']")
$("div[translate='yes']")
Or more specific, using the classes present as well:
$("div.error-msg.ng-scope[translate='no']")
$("div.error-msg.ng-scope[translate='yes']")
It would be best to find something unique in the surrounding HTML structure. The easiest way would be to add a unique class to just the instances you want to edit, but otherwise the parents, etc are often heplful.