MS-RDG-Device-Redirection - Get decimal value for configuration

gistfile1.txt

# MS-RDG-Device-Redirection
# https://msdn.microsoft.com/en-us/library/cc243459.aspx

$ByteArray = [System.Array]::CreateInstance([byte], 32)
$ByteArray.Set(0, 1) # Drive redirection disabled
$ByteArray.Set(1, 1) # Printers redirection disabled
$ByteArray.Set(2, 1) # Serial ports redirection disabled
$ByteArray.Set(3, 1) # Clipboard redirection disabled
$ByteArray.Set(4, 0) # Plug and play devices redirection enabled
$ByteArray.Set(29, 0) # Device redirection is controlled by bits 0..4
$ByteArray.Set(30, 0) # Device redirection is controlled, first, by bit 29 and then by bits 0..4

Write-Output ([System.BitConverter]::ToInt32($ByteArray, 0))

You have a slight problem here in that you are working on a 32-byte array instead of a 32-bit one. You really want something more like this.

Note:: I'm forcing it to an unsigned 64 bit integer so you can drag the binary out of it if you wanted (and to avoid PS's propensity to take undeclared numeric types as doubles and give the output in scientific notation).

# MS-RDG-Device-Redirection
# https://msdn.microsoft.com/en-us/library/cc243459.aspx

$value = [uint64]87608012759367680   #  important, the base value for the RADIUS attribute (in decimal) if crafting a generic RADIUS type
$value = [uint64]0  #  if making a RADIUS attribute for NPS with the Microsoft Vendor selection
#$value += [uint64]([Math]::Pow(2,0))  # Drive redirection disabled
#$value += [uint64]([Math]::Pow(2,1))  # Printers redirection disabled
#$value += [uint64]([Math]::Pow(2,2))  # Serial ports redirection disabled
#$value += [uint64]([Math]::Pow(2,3))  # Clipboard redirection disabled
#$value += [uint64]([Math]::Pow(2,4))  # Plug and play devices redirection enabled
$value += [uint64]([Math]::Pow(2,29)) # Disable all device redirection
#$value += [uint64]([Math]::Pow(2,30)) # Enable all device redirection

Write-Output $value

Just uncomment the lines you want to activate in the policy. This will give you the proper decimal value (where setting per-byte won't)