Countdown Timer Pause and Resume Button

Hey guys, I'm new so please forgive me for the simple questions that I'm coming up with. You are all helping me out so much and I apprecaite it very much.

I am trying to create a countdown timer my class. I want to give them an amount of time to discuss a certain topic then bring them all back together as a class to discuss what they talked about.

Anyway the start buttons work. I want to insert a button that will pause this (so the we can clarify something if needed) and then when I click start it will continue right where it left off.

Sub CountDown()

If Range("Time") <= 0 Then
GoTo 10

Else
Range("Time") = Range("Wanted")

10:
End If

20:
Dim PauseTime, Start

PauseTime = 1
Start = Timer
Do While Timer < Start + PauseTime
DoEvents

Loop

Range("Time").Value = Range("Time").Value - 1

If Range("Time").Value <= 0 Then

MsgBox "STOP"
Exit Sub
End If

GoTo 20
End Sub