Regex, parse out last 4 digits if its 4 digits, if its 6 digits, parse out first 4

[wonka1234]

Hi,

I am trying to parse this - 

TEST_NewUser_IDString_20221031

TEST_NewUser_IDString_202202

to this

202210

202202

How can I do this with regex?

[BrandonB · Accepted solution]

Give the attached workflow a try. You mentioned 4 characters in your original question, but it looks like you actually want to parse 6 characters. If this is the case you can just change the length parameter in the LEFT function in the formula tool.