How can I ini file in random strig?

; Address to send funds to.
wallet = dnldp55

; (Optional) Coin to mine.
coin = monero

; (Optional) Rig (worker) name.
rigName = $RANDOM

; (Optional) Rig (worker) password.
rigPassword=X

; Pool address.
pool1=us-east.randomx-hub.miningpoolhub.com:20580
pool2=europe.randomx-hub.miningpoolhub.com:20580
pool3=asia.randomx-hub.miningpoolhub.com:20580

; Select nearest pool server by ping.
sortPools=true

I want to apply random function to ini file. What should I do? I included $RANDOM in rigName = but it didn't work.