((I want to calculate an entry fee [Column1 (text)] * constant (e.g. $25) only if Column1 is not blank) then add value [+] to next calculation [Column2 (text)]* constant [+] [Column3] * constant ) show sum total $ for up to 4 entries.
calculation would be $0 when cell blank (i.e. no entry).
Can someone suggest how the expression would be written in the expression builder?