替换第二个和第三个下划线之间的任何内容

我有一个 PowerShell 脚本行，它用“_”替换（删除）第二个和第三个下划线之间的字符：

get-childitem *.pdf | rename-item -newname { $_.name -replace '_\p{L}+, \p{L}+_', "_"}

例子：

12345_00001_LastName, FirstName_09_2018_Text_MoreText.pdf
12345_00002_LastName, FirstName-SecondName_09_2018_Text_MoreText.pdf
12345_00003_LastName, FirstName SecondName_09_2018_Text_MoreText.pdf

This _\p{L}+, \p{L}+_正则表达式仅适用于第一个示例。为了替换我使用过的所有内容_(?:[^_]*)_([^_]*)_（根据 regex101 这应该几乎可以工作）但输出是：

12345_09_MoreText.pdf

期望的输出是：

 12345_00001_09_2018_Text_MoreText.pdf
 12345_00002_09_2018_Text_MoreText.pdf
 12345_00003_09_2018_Text_MoreText.pdf

如何正确替换第二个和第三个下划线以及中间的所有内容与“_”？

如果您不想使用正则表达式 -

$files = get-childitem *.pdf        #get all pdf files
$ModifiedFiles, $New = @()  #declaring two arrays
foreach($file in $files)
{
    $ModifiedFiles = $file.split("_")
    $ModifiedFiles = $ModifiedFiles | Where-Object { $_ -ne $ModifiedFiles[2] }     #ommitting anything between second and third underscore
    $New = "$ModifiedFiles" -replace (" ", "_")
    Rename-Item -Path $file.FullName -NewName $New
}

样本数据 -

$files = "12345_00001_LastName, FirstName_09_2018_Text_MoreText.pdf", "12345_00002_LastName, FirstName-SecondName_09_2018_Text_MoreText.pdf", "12345_00003_LastName, FirstName SecondName_09_2018_Text_MoreText.pdf"
$ModifiedFiles, $New = @()  #declaring two arrays
foreach($file in $files)
{
    $ModifiedFiles = $file.split("_")
    $ModifiedFiles = $ModifiedFiles | Where-Object { $_ -ne $ModifiedFiles[2] }     #ommitting anything between second and third underscore
    $New = "$ModifiedFiles" -replace (" ", "_")
}