You need the 3rd party tools to transfer ATR images from/to CF, to be used on your PC.
viewtopic.php?f=17&t=1592If we are talking standard Atari DOS files, I would suggest you boot your Atari with MyBIOS.
Boot as normal, this will set D1 as drive on your CF.
Connect your 1050 as D3: (or any other drive ID that is free/not used by CF).
Enter MyDOS using the DOS command.
Copy files from D3: to D1:
If we are taking specific disks, I would boot up in IMAGE mode, holding START on the MyBIOS-screen.
Connect your 1050 as D1:
Select any empty slot.
Hit > enter a name and confirm with Y when the border is red.
Wait until diskcopy is finished.
Repeat this on other slots and other disks.
Remove CF en pop it in your PC, extract and save them as yourname.ATR
Done.