Search notes:

WMIC.exe logicalDisk

The following command shows drive letters that are in use:
C:\Users\Rene>wmic logicalDisk get providerName, deviceId, description
Description        DeviceID  ProviderName
Local Fixed Disk   C:
CD-ROM Disc        D:
Removable Disk     E:
Network Connection H:        \\nasint.jb.xy\user01\rene
Network Connection M:        \\nasint.jb.xy\misc
Network Connection P:        \\nasint.jb.xy\project
In order to limit the query to «mapped drives» (net use …), driveType must be 4:
c:\> wmic logicalDisk where driveType=4 get providerName,deviceId,description

See also

WMIC.exe

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