Search files on specific depth level

How can I search for a file in a specific subfolder that constantly changes name. Max depth should be at -1. My current script is:

$FilePathStat = “C:\NG_auto_project\nextgene_to_import”
$FileNameStat = “*_StatInfo.txt”
$Outputa = Get-ChildItem -Path $FilePathStat -Filter $FileNameStat | select -ExpandProperty FullName

Can you pliz help me?

THX