This KB article provides steps to add TrustedIP's in a List rule, this provides capability to add TrustedIP's through a file upload or adding them in bulk manually.
CA Risk Authentication
CA Advanced Authentication
Please see the images below to create a List rule to upload the IP address which you want to trust. Make this custom list rule above the UNTRUSTEDIP rule. First screen shot provide instructions to create a new rule.
The data format to upload it via a file is like below, the content below is excerpt from the ip.csv file which was tested.
10.11.x.x
10.20.x.x
10.10.x.x
20.20.x.x
30.30.x.x
After the rule is created and also after uploading the data, Migrate to Production should be done and then refresh the server cache.