Automation: Creating a Variable with RegEx and using it inside another fuction

Hello dear Atlassian-Community,

I am currently trying to build something that would make an old automation of mine way shorter and incredibly more efficient, but the whole idea hinges on "being able to create a RegEx dynamically and handing it over to another function"

Here is the functional part of my concept:

0) Trigger: Doesn't matter for this case

1) Action: Create Variable

This is a comma separated gathering of calculations done beforehand. In the real world application this will be provided by a lookupObjects-List-Iteration and (hopefully clever) replace-functions.

Name: myVarInput
Value: 1~A, 111~B, 1~C, 11~D

Worth noting: "More 1 = more important" I would want to get "B" back in some way and i thought of trying with regEx.

2) Action: Create Variable

Name: maxOnesMinusOne
Value: 2

We will not talk about how I will get the max size / maximum numbers of "1"s from {{myVarInput}} here and subtract 1 - lets just assume I get the Value 2 somehow ;)

EDIT: I have found and shared a way to extract this value in the comments. I still feel it remains out of scope here but for anyone there now exists two-create-variable-steps solution that doesn't even require any RegEx to work. Crazy, I know.

3) Action: Create Variable

Name: myDynamicBlock
Value: [1]\{1,{{maxOnesMinusOne}}\}

Note: I would want to have the output [1]{1,2} for our example input

4) Action: Create Variable

Name: regExTest
Value: {{myVarInput.replace(myDynamicBlock,"0")}}

Note: Following our example line, I would want to have the output 0~A, 01~B, 0~C, 0~D here.

5) Create Variable Action with Further refinement (out of scope for this question, because it only requires a "fixed" RegEx at this point):

Next step would be {{regExTest.split(", ").remove("0~.*")}} (RegEx test pending) to have only the most important (multiple possible) entries left.

Questions:

1) Is the handover from maxSizeMinusOne to myDynamicBlock possible (can i exclude curly brackets somehow)?

2) Is the handover from myDynamicBlock to regExTest possible? (how do i get it to execute properly)

Edit/carifications:

- {{myVarInput}} is vastly reduced in complexity and simply gauging the size of the individual chunks separated by commas will not work in the real world application.

- I have corrected some spelling/consistency mistakes after posting

- Upon some further investigation, I have found this post with an answer related to my musings from @Bill Sheboy - Solved: Jira automation - using variable in another variab... maybe there is indeed some hope for me?

- the 4th action initially and wrongs used {{myVar.replace[...] instead of {{myVarInput.replace[...] - i have adjusted this to avoid confusing anyone reading or trying to reproduce this in the future. Thanks to everyone for noticing!

Kind regards,

Ludwig