All the code comes with MQX, you just need to put two examples together. Start with:
c:\Freescale\Freescale_MQX_4_0\rtcs\examples\shell\
which contains a shell command for FTP client ("ftp"). Get familiar with using it, connect with a remote server and transfer a file to ramdisk.
In second step, you take
c:\Freescale\Freescale_MQX_4_0\mfs\examples\sdcard\
which has a task that mounts MFS on SDCARD. Integrate it with the rtcs/examples/shell.
By the way, the actual version is MQX 4.0.1, very soon, MQX 4.0.2 will be out.