You can use the "Extract with regular expression" processor to check if a column contains only alphanumerical characters.
In a prepare recipe you can click on "Add a new step", search for regex, and click on "Extract with regular expression".
If you want to check if the column contains only alphanumerical content you can :
- put "^[a-zA-Z0-9_]*$" in the regular expression field
- and check 'create a special found column'
If you want to extract all alphanumerical occurrences :
- you can put "([a-zA-Z0-9_]+)" in the regular expression field
- and check "extract all occurrences"
Hope it helps,
I can't reproduce your issue. As you can see in the screenshot, the regex works well for a cell with only "ABC000006498287" in it.
Now if you have other characters in the cell it will fail. For instance, I added a trailing space in line 2.
Hope it helps