Sorry, but couldn't find any but seeming mutually contradictory information on the replace string extension. Is it alive on en.Wikibooks (meaning I have a likely precedence flaw) or not is WAS my 'Need'... but I answered my own question remembering I used it successfully a couple of months ago in another template.
- I'm continuing because...
- the one reference page has two box headers which seem to contradict themselves at the very page top, and the bugzilla linked there seems to be open and unresolved--but with a mention that everything there was now incorporated into the wiki magicword system, but that and one other.
If I'm making the right mappings from my history:
- Extension:Replace Text probably has the two warring box notices right up top... as I went to Bugzilla from there.
- Wikitext parser/Core parser functions - says it should work (but someone ought to reconcile these!)
- Extension:String Functions#replace is a very unhelpful section header with an apparently included empty sub-page.
I'd take it on, but making sure of my ground in this realm of computer science geeks is like translating German to English to read how an Electrical geek like me has to use it! best regards,