You may want to play with Parameter 3 (locktime) of the CreateRawTransaction RPC on Testnet and see if that does what you want (it's not really CLTV). Otherwise, I would do some googling - it generally should be about the same as in Bitcoin. Also, look at this issue if doing locktimes since there is a nuance depending on which method you use (time vs. block height).
And use a lot of caution any time you are working with locktimes to avoid losing access to funds.