drm proxy settings with domain account

Hi,

how do I input the credentials for domain authenticated proxy server?

I have tried several inputs like domain\username, domain/username, domain\\username... but nothing seems to work.

When I check the drm logs there is always

Initializing DMSDownloader auth:DMSAuthParams [null/ ] ...

Does the "null" represents a domain?

How do I change the "null" to some domain?

Thank you.