i need to fill one field with the concatenation of 2 custom fields like this:

{custrecord_accountnumber} ({custrecord_bankname})

so i get something like

1232313 (BOA)

in the field. But i get an error saying the formula has an error. I could not find any sample on how to concatenate strings like this. I also tried with + and with

concat

Do you have any suggestion? Thanks

do it in code, rather than a 'formula'. e.g.

${custrecord_accountnumber} (${custrecord_bankname})