$cert = New-SelfSignedCertificate `
    -Subject "Always Encrypted Sample Cert" `
    -CertStoreLocation Cert:CurrentUserMy `
    -Type Custom
$thumbprint = $cert.ThumbPrint
Write-Verbose "Cert thumbprint $thumbprint"

$smoDatabase.ExecuteNonQuery(@"
CREATE COLUMN MASTER KEY [$($MasterKeyName)]
WITH (
    KEY_STORE_PROVIDER_NAME = 'MSSQL_CERTIFICATE_STORE',
    KEY_PATH = N'CurrentUser/My/$($thumbprint)'
);
"@);

CREATE COLUMN ENCRYPTION KEY key_name
WITH VALUES (
    COLUMN_MASTER_KEY = [$($MasterKeyName)],
    ALGORITHM = 'RSA_OAEP',
    ENCRYPTED_VALUE = $EncryptedValue
);

C:Userszippy> $certProvider = new-object 'System.Data.SqlCLient.SqlColumnEncryptionCertificateStoreProvider'
C:Userszippy> $byte = [byte[]]@() # I don't know what to put here
C:Userszippy> $certProvider.EncryptColumnEncryptionKey('Current User/My/0879e6a82f7fe3f88e91e37e69f08c8fa1f4cc48', 'RSA_OAEP', $byte)