Use an arraylist in a comparison operation

Hello,

here is a short code.

$infos = $null
$infos = @{}
$infos = @{ 
"toto" = "tutu" ; 
"hello" = "hellu"
<#...#>
 }

$extensions = $null
$extensions = New-Object -TypeName 'System.Collections.ArrayList';
$extensions = ("txt", "cmd","ps1" <#...#>)


foreach
($key in $infos.keys)
{
$key
    Get-ChildItem ".\Desktop\test" -Recurse | Where-Object {-not $_.PSIsContainer -and ($_.Extension -eq ".frm" -or $_.Extension -eq ".ps1" -or $_.Extension -eq ".txt")} | 
    ForEach-Object {(Get-Content $_.FullName) | 
    ForEach-Object { 
    $_ -replace [regex]::Escape($key), $($infos[$key]) } | Set-Content $_.FullName
    }
}

I want to use an arraylist containing a list of file extensions when I do my extensions checks in there:

-and ($_.Extension -eq ".frm" -or $_.Extension -eq ".ps1" -or $_.Extension -eq ".txt")

I'd like to replace it with something similar to:

-and ($_.Extension -eq $extensions)

Is there anyway clean way to writting this?

Thank you!