Script to retrieve values for your bank transfer coordinates, stored in encrypted gpg file. Put script in your PATH and don't forget chmod +x. Obviously you need to prepare your transfer coordinates file. This will ask your gpg passcode on runtime.

santa

#!/bin/bash
#-----------------------------#
# Example content of .gpg file:
# declare -a a=(01 02 03 04 05)
# declare -a b=(01 02 03 04 05)
# declare -a c=(01 02 03 04 05)
# declare -a d=(01 02 03 04 05)
# ....
# Usage: santa a1 e4 j2
#-----------------------------#

. <(gpg -qd ~/path/to/your/file.gpg)

# Parsing input values
coordinate1=$1
coordinate2=$2
coordinate3=$3

letter1=${coordinate1:0:1}
letter2=${coordinate2:0:1}
letter3=${coordinate3:0:1}

number1=$((${coordinate1:1:1}-1))
number2=$((${coordinate2:1:1}-1))
number3=$((${coordinate3:1:1}-1))

pattern1=$letter1[$number1]
pattern2=$letter2[$number2]
pattern3=$letter3[$number3]

# Making shure no one could scroll your term to see input and corresponding output 
clear

echo ${!pattern1} ${!pattern2} ${!pattern3}