# Question/Problem regarding Regular Expression Capturing GROUPS: "$regexp(x,e,r,c)" vs "Replace with regular expression" (ONLY available via .MTA/Quick Action) **URL:** https://community.mp3tag.de/t/question-problem-regarding-regular-expression-capturing-groups-regexp-x-e-r-c-vs-replace-with-regular-expression-only-available-via-mta-quick-action/68931 **Category:** Support **Created:** [June 24, 2025, 12:34am UTC](https://community.mp3tag.de/t/question-problem-regarding-regular-expression-capturing-groups-regexp-x-e-r-c-vs-replace-with-regular-expression-only-available-via-mta-quick-action/68931 "2025-06-24T00:34:01Z") **Posts on this page:** 1 **Showing post:** 2
### Author: ![ohrenkino](https://community.mp3tag.de/user_avatar/community.mp3tag.de/ohrenkino/32/4843_2.png) [@ohrenkino](https://community.mp3tag.de/u/ohrenkino) #### Post date: [June 24, 2025, 5:27am UTC](https://community.mp3tag.de/t/question-problem-regarding-regular-expression-capturing-groups-regexp-x-e-r-c-vs-replace-with-regular-expression-only-available-via-mta-quick-action/68931/2 "2025-06-24T05:27:46Z")
See here: > [@A little regex help with dots and spaces](https://community.mp3tag.de/t/a-little-regex-help-with-dots-and-spaces/66709/16): > > This is because, when using a scripting function in the replacement part of the $regexp function, the scripting function is evaluated before the replacement occurs. This is due to the evaluation order of the scripting language. The action Replace with Regular Expression supports scripting functions in the replacement part. This won't work on macOS, because the underlying [ICU regular expression engine](https://unicode-org.github.io/icu/userguide/strings/regexp.html) does not support \u. In my experiments, the Java 8 flavour on regex101 is the closest match… --- _[View the full topic](https://community.mp3tag.de/t/question-problem-regarding-regular-expression-capturing-groups-regexp-x-e-r-c-vs-replace-with-regular-expression-only-available-via-mta-quick-action/68931)._