[powershell] How to properly -filter multiple strings in a PowerShell copy script

I am using the PowerShell script from this answer to do a file copy. The problem arises when I want to include multiple file types using the filter.

Get-ChildItem $originalPath -filter "*.htm"  | `
   foreach{ $targetFile = $htmPath + $_.FullName.SubString($originalPath.Length); ` 
 New-Item -ItemType File -Path $targetFile -Force;  `
 Copy-Item $_.FullName -destination $targetFile }

works like a dream. However, The problem arises when I want to include multiple file types using the filter.

Get-ChildItem $originalPath ` 
  -filter "*.gif","*.jpg","*.xls*","*.doc*","*.pdf*","*.wav*",".ppt*")  | `
   foreach{ $targetFile = $htmPath + $_.FullName.SubString($originalPath.Length); ` 
 New-Item -ItemType File -Path $targetFile -Force;  `
 Copy-Item $_.FullName -destination $targetFile }

Gives me the following error:

Get-ChildItem : Cannot convert 'System.Object[]' to the type 'System.String' required by parameter 'Filter'. Specified method is not supported.
At F:\data\foo\CGM.ps1:121 char:36
+ Get-ChildItem $originalPath -filter <<<<  "*.gif","*.jpg","*.xls*","*.doc*","*.pdf*","*.wav*",".ppt*" | `
    + CategoryInfo          : InvalidArgument: (:) [Get-ChildItem], ParameterBindingException
    + FullyQualifiedErrorId : CannotConvertArgument,Microsoft.PowerShell.Commands.GetChildItemCommand

I have various iterations of parentheses, no parentheses, -filter, -include, defining the inclusions as variable (e.g., $fileFilter) and each time get the above error, and always pointing to whatever follows -filter.

The interesting exception to that is when I code -filter "*.gif,*.jpg,*.xls*,*.doc*,*.pdf*,*.wav*,*.ppt*". There are no errors, but I and get no results and nothing back to the console. I suspect I've inadvertently coded an impicit and with that statement?

So what am I doing wrong, and how can I correct it?

Get-ChildItem $originalPath\* -Include @("*.gif", "*.jpg", "*.xls*", "*.doc*", "*.pdf*", "*.wav*", "*.ppt")

Something like this should work (it did for me). The reason for wanting to use -Filter instead of -Include is that include takes a huge performance hit compared to -Filter.

Below just loops each file type and multiple servers/workstations specified in separate files.

##  
##  This script will pull from a list of workstations in a text file and search for the specified string


## Change the file path below to where your list of target workstations reside
## Change the file path below to where your list of filetypes reside

$filetypes = gc 'pathToListOffiletypes.txt'
$servers = gc 'pathToListOfWorkstations.txt'

##Set the scope of the variable so it has visibility
set-variable -Name searchString -Scope 0
$searchString = 'whatYouAreSearchingFor'

foreach ($server in $servers)
    {

    foreach ($filetype in $filetypes)
    {

    ## below creates the search path.  This could be further improved to exclude the windows directory
    $serverString = "\\"+$server+"\c$\Program Files"


    ## Display the server being queried
    write-host “Server:” $server "searching for " $filetype in $serverString

    Get-ChildItem -Path $serverString -Recurse -Filter $filetype |
    #-Include "*.xml","*.ps1","*.cnf","*.odf","*.conf","*.bat","*.cfg","*.ini","*.config","*.info","*.nfo","*.txt" |
    Select-String -pattern $searchstring | group path | select name | out-file f:\DataCentre\String_Results.txt

    $os = gwmi win32_operatingsystem -computer $server
    $sp = $os | % {$_.servicepackmajorversion}
    $a = $os | % {$_.caption}

    ##  Below will list again the server name as well as its OS and SP
    ##  Because the script may not be monitored, this helps confirm the machine has been successfully scanned
        write-host $server “has completed its " $filetype "scan:” “|” “OS:” $a “SP:” “|” $sp


    }

}
#end script

use the include is the easiest way as per

http://www.vistax64.com/powershell/168315-get-childitem-filter-files-multiple-extensions.html