Replacing whole string with another with Actions

How can I use Actions/Replace to change the whole tag from one string to another? The strings I want to use have spaces and multiple words, and the "only as whole word" thing is useless except for single words. Is there an alternative?

I am not sure what you mean.
It should be not problem to replace "Voldemort" with "He, who must not be named".
Or replace "This is the string I don't like" with "much better now".
Can you give an example?

I have a script that changes
"the platinum collection (2011 remaster)" to "the platinum collection (queen)", and
"the platinum collection" to "the platinum collection (blancmange)",
but accidentally running it more than once causes things like
"the platinum collection (blancmange) (queen)". The problem is because they are treated as parts of the tag's string and not the whole string.

I have a whole bunch of other scripts that can be run many times (namely a big one to remove all the "remastered" tag crap in my collection) but only changes the stuff once, because I like to make sure it's changed. So can this be done in this case?

if you want to have the check that something is exactly a certain string, then use
"Replace with regular expression"
e.g.
Search string: ^the platinum collection$
should really only produce hits for "the platinum collection" and not "the platinum collection (queen).

Please note that you have to demask all special characters for the pseudo-regular expression, like ( should become ( if you use it in the search string.

It worked! Thanks.

I've already created a script that removes all the "remastered" variations in all of my MP3 album and title tags, and luckily the "." wildcard came in useful for all the different years listed, otherwise the script would've been huge and unwieldy.