Regex to selectively grab individual tags?

[Sidetrack]

I've got some hierarchical tags that I'd like to "move" to a custom column so I can easily use them to make collections on my PRS-T1. There is a lot of this management that I want to to do so I'm hoping to use the Search&Replace dialog to do it.

I expected that something like "Accolade\.(.*)" in the regex field would let me extract the information I want but it seems to grab the rest of the tags as well. What am I missing to get from this:
{tags}
Places.Africa, Imperialism, Accolade.100 best.Radcliffe's, Accolade.100 best.Some Prize.1958, Accolade.100 best.Modern Library, Trading posts, Degeneration, People.Europeans

to this and this:
{#accolades}
100 best.Radcliffe's, 100 best.Modern Library Readers, 100 best.Modern Library, Trading posts

{tags}
Places.Africa, Imperialism, Trading posts, Degeneration, People.Europeans

[chaley]

When operating on columns such as "tags" that contain multiple items, the search/replace operation is applied to every item, item by item. The search is not a selector. Instead the text matched by the search regexp is replaced by the "replace" expression. Your expression says to modify only tags beginning with "Accolade.". All other tags are passed through unmodified.

The way to get what you want is to have the S/R modify every tag, removing some or all of the text. All text is removed if the tag does not begin with the desired word (e.g., "Accolade"), otherwise the desired word is removed leaving what follows. For example, the search expression

^((?!Accolade\.).*$)|(Accolade\.)

when used with a null replacement expression will remove the tag completely if it does not begin with "Accolade.", or remove the word "Accolade." leaving whatever follows. The expression

^Accolade\..*$

will remove all tags that begin with "Accolade.".