With 'unofficial LaunchELF' you can move files from MC to USB (and other devices) + you can start an FTP-Server and access your PS2 with an FTP-Client on PC.
Then there is RAD-Host-Client and the host-protocoll (as an alternative to FTP).
The config of FMCB is the 'FREEMCB.CNF' located in either 'SYS-CONF' on MC, or on the root of your USB-Drive.
...and yes, it is possible to access an MC from PC with one of these adapters (currently only the Sony-MC2USB-Adapter, afaik), but you don't need that... Just use a simple USB-Drive and move the file to it, using 'uLE'.
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux