# Using a regular expression in assigning a tag **URL:** \ **Category:** Support\ **Created:** [September 26, 2018, 2:59am UTC](https://community.mp3tag.de/t/using-a-regular-expression-in-assigning-a-tag/43092 "2018-09-26T02:59:52Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![dnanib](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/d/e8c25b/32.png) [@dnanib](https://community.mp3tag.de/u/dnanib)\ **Post date:** [September 26, 2018, 2:59am UTC](https://community.mp3tag.de/t/using-a-regular-expression-in-assigning-a-tag/43092/1 "2018-09-26T02:59:52Z")
I want to update the Album field of a large number of files. The albums names are actually the parent directory names, but with a prefix of album release year. 1984 - Some Album One additional complication is that in years when a band released more than one albums, there are suffixes 'a', 'b' in order on the directory name: 1985a - Album 1 1985b - Album 2 I want to strip out the year, the suffix if any, and space-dash-space combination and use the remainder to fill the ID3 Album field. This does not seem to work (Convert \> Tag - Tag): $regexp(%\_directory%, '^\d{4}[a-z]? - ','') What am I missing? ---
**Author:** ![ohrenkino](https://community.mp3tag.de/user_avatar/community.mp3tag.de/ohrenkino/32/4843_2.png) [@ohrenkino](https://community.mp3tag.de/u/ohrenkino)\ **Post date:** [September 26, 2018, 4:31am UTC](https://community.mp3tag.de/t/using-a-regular-expression-in-assigning-a-tag/43092/2 "2018-09-26T04:31:30Z")
> [@dnanib](#): > > `$regexp(%_directory%, '^\d{4}[a-z]? - ','')` If I see that correctly, then you have a blank behind the comma in front of the apostrophe. Strip that and everything should be working: `$regexp(%_directory%,'^\d{4}[a-z]? - ','')` ---
**Author:** ![dnanib](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/d/e8c25b/32.png) [@dnanib](https://community.mp3tag.de/u/dnanib)\ **Post date:** [September 26, 2018, 4:45am UTC](https://community.mp3tag.de/t/using-a-regular-expression-in-assigning-a-tag/43092/3 "2018-09-26T04:45:52Z")
Thanks for the pointer. This is exactly what worked: $regexp(%\_directory%,'^\d{4}[a-z]? - ',) ---
**Author:** ![system](https://community.mp3tag.de/uploads/default/original/2X/c/ce7035d426cb755a7916793326d23b465222a407.png) [@system](https://community.mp3tag.de/u/system)\ **Post date:** [February 9, 2026, 12:27pm UTC](https://community.mp3tag.de/t/using-a-regular-expression-in-assigning-a-tag/43092/4 "2026-02-09T12:27:41Z")