Create unique filename by adding incremental number - filenames

Question

I'm trying to increment file names if a previously numbered one exists.
For example, it should check if "Example.csv" exists. If so, the new file should be called "Example2.csv", then "Example3.csv", "Example4.csv" and so on. Here's my code so far:
$fileNum = 2
; The $month variable is defined earler in the script but I'll define another var for this example
$month = "January"
If FileExists("Emissions Log - " & $month & ".csv") Then
If FileExists("Emissions Log - " & $month & $fileNum & ".csv") Then
$fileNum += 1
$file = FileOpen("Emissions Log - " & $month & $fileNum & ".csv", 1)
Else
$file = FileOpen("Emissions Log - " & $month & $fileNum & ".csv", 1)
EndIf
Else
$file = FileOpen("Emissions Log - " & $month & ".csv", 1)
EndIf

Answer 1

In order to do that, you must loop the filenames.
$month = "January"
For $i = 0 To 1000 ;max file versions is set to 1000
If $i = 0 Then
$num = ''
Else
$num = $i
EndIf
If Not FileExists("Emissions Log - " & $month & $num & ".csv") then
$file = FileOpen("Emissions Log - " & $month & $num & ".csv", 1)
ExitLoop
EndIf
Next

Answer 2

I'm trying to increment file names if a previously numbered one exists.
While FileExists() StringReplace(). Example:
Func _FilenameUnique(Const $sFilenameRequested, Const $sDelimiter = '-', Const $iCountStart = 2)
Local $iError = 0, _
$iCount = $iCountStart - 1
Local $sFilenameUnique = $sFilenameRequested
While FileExists($sFilenameUnique) And Not $iError
$iCount += 1
$sFilenameUnique = StringReplace($sFilenameRequested, '.', $sDelimiter & $iCount & '.', -1)
$iError = #error
WEnd
Return SetError($iError, $iCount, $sFilenameUnique)
EndFunc
$sFilename = _FilenameUnique('C:\path\file.csv', '') functions as requested. Include current time alternatively:
$sFilename = 'C:\path\file_' & #YEAR & #MON & #YDAY & #HOUR & #MIN & #SEC & '.csv'