For all those using wild card certificates for RDS installations, I have written a script that allows you to import and configure the wild card certificate on all RDS Roles.
It is advised that the script is run on the RD Connection Broker.
Ensure the Certificate is in PFX format and stored locally in a directory like c:\Cert\RDS\. You will need to specify the location of the certificate when running the script.
When specifying the connection broker ensure you use the FQDN not the server or HA name.
Ryan Mangan's IT Blog 