Powershell random Variable generator

I am pretty new to powershell but in my current program I need to assign a variable to a Word

$BtnEntrer2.Add_Click({
if ($Cbchoix.Text -eq "Quitter"){


$tabControl.SelectedTab = $TabPage5
Sleep 3
$FormRPS.Close()

This part is the bugged part
  
if ($Cbchoix.Text -eq "Roche") {$playerMove = "Rock"
$computerMove = Get-Random "Rock","Paper" ,"Scissors"}

if ($Cbchoix.Text -eq "Papier") {$playerMove = "Paper"
$computerMove = Get-Random "Rock","Paper" ,"Scissors"}
if ($Cbchoix.Text -eq "Ciseau") {$playerMove = "Scissors"
$computerMove = Get-Random "Rock","Paper" ,"Scissors"}

Then after the computer move is chosen i got this code going on

switch ($computerMove)
 {
  
  "Rock" { #The computer picked rock)
  
   if ($playerMove -eq "Rock") {
    $noTied += 1 #Increment count by 1
    $percentageTied = ($noTied / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage6 
   }
  
   if ($playerMove -eq "Paper") {
    $noWon += 1 #Increment count by 1
    $percentageWon = ($noWon / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage3 
   }
   
   if ($playerMove -eq "Scissors") {
    $noLost += 1 #Increment count by 1
    $percentageLost = ($noLost / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage4 
   }
  }
 
 
  "Paper" { #The computer picked paper
  
   if ($playerMove -eq "Rock") {
    $noLost += 1 #Increment count by 1
    $percentageLost = ($noLost / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage4 
   }
  
   if ($playerMove -eq "Paper") {
    $noTied += 1 #Increment count by 1
    $percentageTied = ($noTied / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage6 
   }
  
   if ($playerMove -eq "Scissors") {
    $noWon += 1 #Increment count by 1
    $percentageWon = ($noWon / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage3 
   }
  }
  "Scissors" { #The computer picked Scissors
  
   if ($playerMove -eq "Rock") {
    $noWon += 1 #Increment count by 1
    $percentageWon = ($noWon / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage3 
   }
  
   if ($playerMove -eq "Paper") {
    $noLost += 1 #Increment count by 1
    $percentageLost = ($noLost / $noPlayed) * 100
   $tabControl.SelectedTab =$TabPage4 
   }
  
   if ($playerMove -eq "Scissors") {
    $noTied += 1 #Increment count by 1
    $percentageTied = ($noTied / $noPlayed) * 100
    $tabControl.SelectedTab =$TabPage6 
   }
  }
 }

Basically I want the $computermove to pick either Rock paper or scissor then i want to change the tab depending on if its a win a lost or a tie (tabpage3 is win 4 is lost and 6 is tie)