Powershell - Referencing part of file name string

I am trying to extract the first part of a file name, then move to a corresponding folder with powershell. The filename looks something like "X02348957 RANDOM WORDS HERE" - I'm trying to get powershell to only look at the X02348957. The X#'s are also different lengths, so I can't just do it based on a location variable (like read everything 8 spaces to the left - the number won't always be eight spaces).

Here is my code in progress so far;

# Retrieve list of files
# $sDir = Source Directory
$sDir = "U:\Test\"

# Generate a list of all files in source directory
$Files = (Get-ChildItem $sDir)

# $tDir = Root Target Directory
$tDir = "N:\USERS\Username\General\Test\"

# Loop through our list of file names
foreach($File in $Files)
{
# $wFile is the working file name
$wFile = $File.BaseName

# Here is where the code to make it only move based on the first part of file name would go (the X#)?



# dFold = the destination folder in the format of \\drive\folder\SubFolder\    
$dFold = "$tDir$wFile"

# Test if the destination folder exists
if(Test-Path $dFold -PathType Container)
  {
  # If the folder exists then move the file
  Copy-Item -Path $sDir$File -Destination $dFold

  # Denote what file was moved to where        
  Write-Host $File "Was Moved to:" $dFold
  Write-Host
  }
  # If the folder does not exist, leave file alone
  else 
  {
  # Denote if a file was not moved
  Write-Host $File "Was not moved!"
  }

}