Hi @elsamuel , I don’t think @dr_snglr has any issues formatting the string, it’s successfully done via Java Snippet, but the specific request here is to do it via Knime nodes instead, including the Column Expressions.
If I am not mistaken, that component uses Java Snippet.
@dr_snglr , it can be done via Column Expressions using the regexReplace: regexReplace(column("column1"), "[0-9](?=(?:[0-9]{3})+(?![0-9]))", "$0,")
And if you want to keep only 1 decimal place, you can use the toFixed() function, like this: regexReplace(column("column1").toFixed(1), "[0-9](?=(?:[0-9]{3})+(?![0-9]))", "$0,")