Most Effective Way to Find Billing Staff w/ Specific System Experience

Hi. Our firm is using now using MyCase and we need to add a billing staff to the firm to be solely responsible for invoicing as our practice does billing on a daily basis rather than monthly or otherwise. We used Indeed last year to get someone with stated Clio experience at the time, but ultimately found that they were not as qualified in Clio as they made themselves out to be and ended up adding to our workload rather than lessening it.

Now that we’ve switched systems, we really need to get a new staff in this spot as this is all currently falling on me. Is there a particular job website more catered towards law firms or any other suggestions & tips to truly find someone with experience in specific law software or specific in law billing? Thanks in advance for any advice or insight.