Active Mode just means that the Send Data isn't using Port 21., but instead any Port above 1023 (i.e. 1024 - 65535) that isn't in usage by another Client.
Now I don't recall but you _should_ be able to set the Port used by adding

ortNumber to the end of the Url$ you connect via.
So what you'll likely need to do is Open 2 Connections Concurrently...
One that is using the Random Port, the other that is Default... you'll NEVER be able to SEND data to the Default, but you'll need it to listen.
While the Random Port will both Send / Receive.
Alternatively get your System Admin to set the FTP back to Passive.