# Extract Dynamic Substring from MQTT Tag Path in UDT Expression Tag Ignition 8.3.6

**URL:** <https://forum.inductiveautomation.com/t/extract-dynamic-substring-from-mqtt-tag-path-in-udt-expression-tag-ignition-8-3-6/115633>\
**Category:** Ignition\
**Tags:** perspective\
**Created:** [May 21, 2026, 9:52am UTC](https://forum.inductiveautomation.com/t/extract-dynamic-substring-from-mqtt-tag-path-in-udt-expression-tag-ignition-8-3-6/115633 "2026-05-21T09:52:21Z")\
**Posts on this page:** 1\
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**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [May 21, 2026, 4:51pm UTC](https://forum.inductiveautomation.com/t/extract-dynamic-substring-from-mqtt-tag-path-in-udt-expression-tag-ignition-8-3-6/115633/9 "2026-05-21T16:51:01Z")

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> **[Automation Professionals](https://www.automation-pros.com/modulesales.html)**

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> [@Automation Professionals' Integration Toolkit Module](https://forum.inductiveautomation.com/t/automation-professionals-integration-toolkit-module/74934):
>
> Automation Professionals is pleased to announce the immediately availability of a major upgrade to its free Simulation Aids Integration Toolkit module. The new feature justifying the "major upgrade" language is the implementation of eleven thirty-one new expression functions which use iteration to accomplish complex transforms of datasets and lists, to or from other datasets and lists, applying filtering, ordering, and computed new columns along the way. While there are certain operations that…

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> [@Integration Toolkit Solutions Wiki](https://forum.inductiveautomation.com/t/integration-toolkit-solutions-wiki/105080):
>
> By popular request, I've created this topic to be used in wiki mode for collaborative generation of solutions to particular problems. To keep this neat, please follow these guidelines: New problems seeking solutions should be posted as replies, and the discussion of that problem kept within that comment, wiki-style. A one-line summary should be added to this topic starter, with an embedded link (not on its own line). After posting, be sure to convert the comment to operate in wiki mode.

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