Powershell expand variable in scriptblock - variables

Question

I am trying to follow this article to expand a variable in a scriptblock
My code tries this:
$exe = "setup.exe"
invoke-command -ComputerName $j -Credential $credentials -ScriptBlock {cmd /c 'C:\share\[scriptblock]::Create($exe)'}
How to fix the error:
The filename, directory name, or volume label syntax is incorrect.
+ CategoryInfo : NotSpecified: (The filename, d...x is incorrect.:String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError
+ PSComputerName : remote_computer

Answer 1

You definitely don't need to create a new script block for this scenario, see Bruce's comment at the bottom of the linked article for some good reasons why you shouldn't.
Bruce mentions passing parameters to a script block and that works well in this scenario:
$exe = 'setup.exe'
invoke-command -ComputerName $j -Credential $credentials -ScriptBlock { param($exe) & "C:\share\$exe" } -ArgumentList $exe
In PowerShell V3, there is an even easier way to pass parameters via Invoke-Command:
$exe = 'setup.exe'
invoke-command -ComputerName $j -Credential $credentials -ScriptBlock { & "C:\share\$using:exe" }
Note that PowerShell runs exe files just fine, there's usually no reason to run cmd first.

Answer 2

To follow the article, you want to make sure to leverage PowerShell's ability to expand variables in a string and then use [ScriptBlock]::Create() which takes a string to create a new ScriptBlock. What you are currently attempting is to generate a ScriptBlock within a ScriptBlock, which isn't going to work. It should look a little more like this:
$exe = 'setup.exe'
# The below line should expand the variable as needed
[String]$cmd = "cmd /c 'C:\share\$exe'"
# The below line creates the script block to pass in Invoke-Command
[ScriptBlock]$sb = [ScriptBlock]::Create($cmd)
Invoke-Command -ComputerName $j -Credential $credentials -ScriptBlock $sb