Hi @Bytecrawler, yes that is a limitation of Column Expressions in regular use, and for a long time I thought it couldn’t be achieved at all with Column Expressions, but it turns out that Column Expressions can be coded in a certain way so that a column can self reference the value that was written out for it on the previous row, by storing it in a variable, the same way it can be achieved in Java Snippets. It’s not perfect but it covers many use cases that had previously seemed ‘not possible’.
Examples of how this can be achieved can be found both nodes can be found in the two posts “Java Snippets have long memories” and “Column Expressions have long memories too!” post I referenced above. I hope you find them useful 
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