attach database - verify - detach from a script or a batch file
This one was quite tricky. I didn't figure out how to access DBCC messages, but am working on it. Anyway, this Powershell script attaches databases, executes DBCC CHECKDB and detaches dbs.

# Get database files from where ever they are
$databases = gci "C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data2\*.mdf"
$sqlCmds = @()
# Parse db names from file names somehow and generate attach/check/detach statements
foreach($db in $databases) {
  $dbName = [regex]::Replace($db.Name, "(?i)\.mdf", "")
  $lgName = [regex]::Replace($db.FullName, "(?i)\.mdf", ".ldf")
  $sqlCmds += $("CREATE DATABASE {0} ON (FILENAME = '{1}') LOG ON (FILENAME = '{2}') FOR ATTACH;"  -f $dbName, $db.FullName, $lgName)
  $sqlCmds += $("DBCC CHECKDB ({0});" -f $dbName)
  $sqlCmds += $("EXEC sp_detach_db @dbname='{0}';" -f $dbName)
}

[void][Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.ConnectionInfo")
$conn = new-object Microsoft.SqlServer.Management.Common.ServerConnection
$conn.ConnectionString = "Server=SERVER\INSTANCE;Database=master;Integrated Security=True"
$s = $sqlCmds[0]

# Try and execute the statements   
try {
    foreach($s in $sqlCmds) {
      $ret = $conn.ExecuteNonQuery($s)
      $ret
    }
} catch [system.exception] {
  $_.Exception.ToString()
}