I am unable to run an invoke-command script to install printers on a remote machine. My code works locally, but as soon as I pipe it into Invoke-command, i get errors.

Local:

$Printer = "\\server1\printer1"
(New-Object -Com Wscript.Network).AddWindowsPrinterConnection($Printer)

And this adds the printer just fine. I can do this same command on the remote computer with no issues. But when i tried to execute the command remotely I have the issues.

Remote:

$compname = "computer"
$Printer = "\\server1\printer1"
Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('$Printer')}

Which returns the error "The printer name is invalid"

So I tried to see what the shell was sending to the remote computer with the following code, and everything in the write output looks good, but I still get errors:

Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('$Printer'); write-host "(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('$Printer')"}

Output:

Exception calling "AddWindowsPrinterConnection" with "1" argument(s): "The printer name is invalid. (Exception from
HRESULT: 0x80070709)"
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : ComMethodTargetInvocation
    + PSComputerName        : computer

(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('\\server1\printer1')

Edit 1/5/2015

So I've tried Paul's code with a number of different entries to the argumentlist. All have not worked so far. i think the first 3 are closer to an answer.

-ArgumentList ""\\server1\printer1""
-ArgumentList ""'\\server1\printer1'""
-ArgumentList "\"\\server1\printer1""

Results in:

Invoke-Command : A positional parameter cannot be found that accepts argument '\\server1\printer1'.
At line:1 char:1
+ Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Ne ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Invoke-Command], ParameterBindingException
    + FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.InvokeCommandCommand



-ArgumentList "'\\server1\printer1'"
-ArgumentList \'"\\server1\printer1"'
-ArgumentList \""\\server1\printer1""
-ArgumentList \"\\server1\printer1"

Result in:

Exception calling "AddWindowsPrinterConnection" with "1" argument(s): "The printer name is invalid. (Exception from
HRESULT: 0x80070709)"
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : ComMethodTargetInvocation
    + PSComputerName        : sso-mxl327082y

Try this:

Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Network).AddWindowsPrinterConnection($args[0]); write-host "(New-Object -Com Wscript.Network).AddWindowsPrinterConnection($($args[0]))"} -ArgumentList "\\server1\printer1"

I think it´s because your $printer variable is placed between single quotes, variables between single quotes are not interpreted by powershell. So the printername your function probably gets is "$printer".

In case you wonder it is printed out correctly in your write-host statement because here the single quotes are inside a string.