Expand property in hashtable - arrays

Question

I'm having a simple issue with a script, where I want to run a GCI against a remote server, issue is, the value is combined with another hashtable property, so the GCI fails.
The script reads entries from a two-column .csv, the headers are "server" and "platform"
Here's what I've got:
$ShortDate = (Get-Date).ToString('MM/dd/yyyy')
$CheckServer = #{}
$serverObjects = #() # create a list of server objects
Import-Csv $Dir\Servers.csv | ForEach {
$CheckServer.Server = $_.Server
$CheckServer.Platform = $_.Platform
if (GCI \\$_.Server\c$\log\Completed_Summary_*.html -EA 0 | where {$.LastWriteTime -ge "$ShortDate"}) {
Write-Host "FOUND"
} # end of IF GCI
} # end of For-Each
$serverObjects += New-Object -TypeName PSObject -Property $CheckServer
The problem is that the entry for $_.Server should be SERVER1, SERVER2, SERVER3, etc, all the entries in the servers.csv, instead, the values for both $_.Server and $_.Platform are combined. Such as:
Write-Host "Checking" \\#{Server=SERVER1; Platform=PLATFORM_1}.Server\c$\log\Completed_Summary_*.html
it should show as follows:
Write-Host "Checking" \\SERVER1\log\Completed_Summary_*.html
How do I un-combine them so that the GCI command works?

Answer 1

PowerShell only does simple variable expansion inside strings. For more complex expressions like index operations or accessing object properties/methods it would insert the stringified value of the array or object variable and leave the rest of the operation untouched.
Demonstration:
PS C:\> $array = 23, 42
PS C:\> Write-Host "some $array[1] or other"
some 23 42[1] or other
PS C:\> $object = New-Object -Type PSObject -Property #{Foo=23; Bar=42}
PS C:\> Write-Host "some $object.Foo or other"
some #{Bar=42; Foo=23}.Foo or other
To avoid this you need to either:
assign the resulting value to a variable first and use that variable in the string:
$value = $array[5]
Write-Host "some $value or other"
$value = $object.Foo
Write-Host "some $value or other"
use a subexpression ($(...)):
Write-Host "some $($array[5]) or other"
Write-Host "some $($object.Foo) or other"
use the format operator (-f):
Write-Host "some {0} or other" -f $array[5]
Write-Host "some {0} or other" -f $object.Foo

Answer 2

modify like it
$ShortDate = Get-Date -Hour 0 -Minute 0 -Second 0
$CheckServer = #{}
$serverObjects = #() # create a list of server objects
$Dir="C:\temp"
Import-Csv $Dir\Servers.csv | ForEach {
$CheckServer.Server = $_.Server
$CheckServer.Platform = $_.Platform
if (GCI "\\$($_.Server)\c$\log\Completed_Summary_*.html" -EA 0 | where {$_.LastWriteTime -ge $ShortDate})
{
Write-Host "FOUND"
}
}