Here is an example on how to create a shadow copy from the command line.
The example will cretae a shadow copy and link it to the name shadowcopy for use.

Open the dos window (cmd) and type powershell.

Type in this command:
(Get-WmiObject -list Win32_shadowcopy).Create("c:\","ClientAccessible")

"exit" to exit powershell

Get list of shadow copies, go by the time created:
vssadmin list shadows

Create link to the shadow copy:
mklink /d c:\shadowcopy \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy11

To remove all shadow copies:
vssadmin delete shadows /all