I'm trying to add a custom formula field that converts the transaction line foreign amount to the desired currency ID based on the transaction date. I'm trying to use this formula: TO_NUMBER({transactionlines.foreignamount#converted[4;trandate]}) but I can't get it to work with trandate (it works if I replace trandate with one specific date like 2018-12-31). Is this possible?

wouldn't you have to put trandate in braces since its a field like {trandate}

I tried that and got an error message that says "invalid format."