Launching choosen file in different application, Running in background

Public Sub OpenSnapShotViewer()
    Dim x As Variant
    Dim Path As String
    Dim File As String

    Path = "C:\Program Files\Adobe Reader\adobereader.EXE"
    File = "h:\Snapshots\TempSnap.pdf"

    x = Shell(Path + " " + File, vbNormalFocus)

End Sub

1.How can I change the file name to a different file name with out editing the code?

2.How can I make this happen in the background?

3.Also, does adobe reader use vba, if not how can I access that program without sendkeys?