param(
    [string] $ParamExePath
)

function Run-CallThisExe {
    param(
        [string] $ThisExePath
    )

    Write-Host "ThisExePath: " "$ThisExePath"
    start-process -FilePath $ThisExePath
}

write-host "ParamExePath: " $ParamExePath

Run-CallThisExe -ThisExePath "$ParamExePath"

powershell -command .Untitled1.ps1 -NonInteractive -ParamExePath "C:path with spacesmyapp.exe"

powershell -command .Untitled1.ps1 -NonInteractive -ParamExePath "C:path with spacesmyapp.exe"

powershell -file .Untitled1.ps1 -NonInteractive -ParamExePath "C:path with spacesmyapp.exe"

-Command
    Executes the specified commands (and any parameters) as though they were
    typed at the Windows PowerShell command prompt, and then exits, unless
    NoExit is specified. The value of Command can be "-", a string. or a
    script block.

-File
    Runs the specified script in the local scope ("dot-sourced"), so that the
    functions and variables that the script creates are available in the
    current session. Enter the script file path and any parameters.
    File must be the last parameter in the command, because all characters
    typed after the File parameter name are interpreted
    as the script file path followed by the script parameters.

powershell -command .Untitled1.ps1 -NonInteractive "-ParamExePath 'C:path with spacesmyapp.exe'"

powershell -command ".Untitled1.ps1 -ParamExePath 'C:path with spacesmyapp.exe'" -NonInteractive