Returning value from Start-Process argument - powershell

Question

I have a PowerShell function (Add-EventLogSource) that checks if an event log source exists. If it does not exist and the shell is not elevated, I start a new, elevated shell and call the function again.
I can't seem to get the return values correct. If the event log source does not exist, and I call Add-EventLogSource, I am not getting the return value all the way back to instance that originally called Add-EventLogSource. Can anyone see the problem? The code looks like this:
Function Add-EventLogSource {
Param (
[Parameter(Mandatory=$True)]
$EventLogSource
)
# Check if $EventLogSource exists as a source. If the shell is not elevated and the check fails to access the Security log, assume the source does not exist.
Try {
$sourceExists = [System.Diagnostics.EventLog]::SourceExists("$EventLogSource")
}
Catch {
$sourceExists = $False
}
If ((([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] “Administrator”)) -AND ($sourceExists -eq $False)) { # Shell is elevated...
Try {
New-EventLog –LogName Application –Source $EventLogSource -ErrorAction Stop
}
Catch {
Return "Error"
}
Return "Created"
}
ElseIf ($sourceExists -eq $False) {
$return = Start-Process PowerShell –Verb RunAs -ArgumentList "Add-EventLogSource -EventLogSource $EventLogSource; start-sleep 5" -Wait
Return $return
}
Else {
Return "Exists"
}
}
Thanks.