How to backup more than one database using powershell

Question

I am Trying to backup more than one database using the following script but no luck. I want user to type on command line the database they want to backup, e.g all databases that have "test" at the front like test.inventory, test.sales so i want
user to type test.* and it backs up all databases related to test. Here is the script
    #$date = Get-Date -Format yyyyMMddHHmmss
    #$dbname = 'test.inventory'
    $dbToBackup = "test.inventory"
    cls
    [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SMO") | Out-Null
    [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoExtended") | 
    Out-Null
    [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.ConnectionInfo") 
    | Out-Null
    [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoEnum") | Out-
    Null
    Add-Type -AssemblyName "Microsoft.SqlServer.Smo, Version=10.0.0.0, Culture=neutral,   
    PublicKeyToken=89845dcd8080cc91"
    $server = New-Object Microsoft.SqlServer.Management.Smo.Server($env:ComputerName) 
    $server.Properties["BackupDirectory"].Value = "C:\_DBbackups"
    $server.Alter()
    $backupDirectory = $server.Settings.BackupDirectory
    #display default backup directory
    "Default Backup Directory: " + $backupDirectory
    $db = $server.Databases[$dbToBackup]
    $dbName = $db.Name
    $timestamp = Get-Date -format yyyyMMddHHmmss
    $smoBackup = New-Object ("Microsoft.SqlServer.Management.Smo.Backup")
    #BackupActionType specifies the type of backup.
    #Options are Database, Files, Log
    #This belongs in Microsoft.SqlServer.SmoExtended assembly
    $smoBackup.Action = "Database"
    $smoBackup.BackupSetDescription = "Full Backup of " + $dbName
    $smoBackup.BackupSetName = $dbName + " Backup"
    $smoBackup.Database = $dbName
    $smoBackup.MediaDescription = "Disk"
    $smoBackup.Devices.AddDevice($backupDirectory + "\" + $dbName + "_" + $timestamp +   
    ".bak", "File")
    $smoBackup.SqlBackup($server)
    #let's confirm, let's list list all backup files
    $directory = Get-ChildItem $backupDirectory
    $backupFilesList = $directory | where {$_.extension -eq ".bak"}
    $backupFilesList | Format-Table Name, LastWriteTime

Answer 1

Or i am using this script which backs up everything except tempdb but dont know how to modify this so that it backs up up all test related databases
Is there a way that i use test.*
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SMO") | out-null
$s = new-object ("Microsoft.SqlServer.Management.Smo.Server") $instance
$bkdir = "C:\_DBbackups" #We define the folder path as a variable 
$dbs = $s.Databases
foreach ($db in $dbs) 
     if($db.Name -ne "tempdb") #We don't want to backup the tempdb database 
     $dbname = $db.Name
     $dt = get-date -format yyyyMMddHHmm #We use this to create a file name based on the timestamp
     $dbBackup = new-object ("Microsoft.SqlServer.Management.Smo.Backup")
     $dbBackup.Action = "Database"
     $dbBackup.Database = $dbname
     $dbBackup.Devices.AddDevice($bkdir + "\" + $dbname + "_db_" + $dt + ".bak", "File")
     $dbBackup.SqlBackup($s)