# Regex with word boundary and anchors inside groups
**URL:** https://forum.xbench.net/t/regex-with-word-boundary-and-anchors-inside-groups/757
**Category:** Technical Support
**Created:** [March 26, 2021, 7:40am UTC](https://forum.xbench.net/t/regex-with-word-boundary-and-anchors-inside-groups/757 "2021-03-26T07:40:14Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Denis77](https://forum.xbench.net/u/Denis77)
#### Post date: [March 26, 2021, 7:40am UTC](https://forum.xbench.net/t/regex-with-word-boundary-and-anchors-inside-groups/757/1 "2021-03-26T07:40:14Z")
Hello,
I am trying to find improperly translated segments where a number without thousand separators in source needs to have those thousand separators in target.
Examples:
(1) 10000 =\> 10 000
(2) 200000 =\> 200 000
(3) It costs 20.222222 per unit. =\> the rule must not match this segment because the number is after the decimal point.
(4) 10000m3 =\> 10 000m3
So, the following conditions must be met:
- The first digit in source must not be preceded by , or . another digit.
- The first digit may be preceded by symbol (e.g. currency or mathematic operators).
- The last digit may be at word foundary or followed by unit of measurement / symbol without space (i.e. no word boundary).
My initial expression was this (a similar string would work in .NET regular expressions):
“(^|[^.,0-9])([0-9]{1,3})=1([0-9]{3})=2(\>|[:letter:]|[:symbol:])”
However, this expression fails in my tests, producing very few matches.
In the end I had to create 4 different ones to avoid the initial and final groups, and these expression cover all the real errors:
1. “^([0-9]{1,3})=1([0-9]{3})=2\>” – matches at start of segment, word boundary at end
2. “^.,0-9=1([0-9]{3})=2\>” – matches at other places inside segment, word boundary at end
3. “^([0-9]{1,3})=1([0-9]{3})=2([:letter:]|[:symbol:])” – matches at start of segment, symbol or unit of measurement after the number
4. “^.,0-9=1([0-9]{3})=2([:letter:]|[:symbol:])” – matches at other places inside segment, symbol or unit of measurement after the number
As far as I understand, \< or \> cannot be used inside alternative groups by themselves, and ^ cannot be used by itself either.
Is there any way to create a single expression rather than 4 permutations?
Thank you!
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### Author:  [@Denis77](https://forum.xbench.net/u/Denis77)
#### Post date: [March 26, 2021, 7:43am UTC](https://forum.xbench.net/t/regex-with-word-boundary-and-anchors-inside-groups/757/2 "2021-03-26T07:43:14Z")
It appears that the regex was cleaned up by the forum, so I am reiterating the regex code with spaces inserted to avoid clean-up:
1. " [^ \ . , 0-9] ([0-9])=1([0-9]{3})=2\>" – matches at other places inside segment, word boundary at end
2. “[^ \ . , 0-9] ([0-9])=1([0-9]{3})=2([:letter:]|[:symbol:])” – matches at other places inside segment, symbol or unit of measurement after the number
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### Author:  [@pcondal](https://forum.xbench.net/u/pcondal)
#### Post date: [March 27, 2021, 4:25pm UTC](https://forum.xbench.net/t/regex-with-word-boundary-and-anchors-inside-groups/757/3 "2021-03-27T16:25:06Z")
You could stat with this for sequences of 4 or more digits that are found both in source and also in target:
- Source: `"(<[:digit:]{4,}>)=1" -"\.@1"`
- Target: `@1`
- Regex: `Enabled`
- PowerSearch: `Enabled`
This can be read as:
> Find in the source text a sequence of 4 or more consecutive digits (which are captured in variable @1) that is not preceded by a dot and that also appears in the target text.
If you have more specializations, such as having specific UoM after the digits, I recommend that you add other checklist items to support the specific specialization.
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### Author:  [@Denis77](https://forum.xbench.net/u/Denis77)
#### Post date: [March 28, 2021, 8:02am UTC](https://forum.xbench.net/t/regex-with-word-boundary-and-anchors-inside-groups/757/4 "2021-03-28T08:02:45Z")
Hello,
Thank you very much!
Denis