I've written a small vbs script to perform batch converting, and save error into a seperate log file, hope it'll help someone
Path = Left(WScript.ScriptFullName, Len(WScript.ScriptFullName)-Len(WScript.ScriptName)) ' Obtain path to this script directory
' Clean up all Flash files generated previously
Set WshShell = CreateObject("WScript.Shell")
WshShell.Run "cmd /c del *.swf /s", , True
set P2F = CreateObject("P2F.Server") ' Create Server object
set MyBPOpt=CreateObject("Print2Flash3.BatchProcessingOptions")
Dim FSO, FLD, FIL
Dim strSourceFolder, strDestFolder, strFilename, strErrorLog
Dim wkNow
strSourceFolder = Path & "\DocumentAnnex"
strDestFolder = Path & "\SWF"
'Create the filesystem object
Set FSO = CreateObject("Scripting.FileSystemObject")
'Get a reference to the folder you want to search
set FLD = FSO.GetFolder(strSourceFolder)
IF Not FSO.FolderExists(Path & "\Log") Then
Set objFolder = FSO.CreateFolder(Path & "\Log")
END IF
'Generate YYYYMMDDMMSS serial for log filename
wkNow= Year(Now())
wkNow= wkNow & Right("0" & Month(Now()) , 2)
wkNow= wkNow & Right("0" & Day(Now()) , 2)
wkNow= wkNow & "_" & Right("0" & Hour(Now()) , 2)
wkNow= wkNow & Right("0" & Minute(Now()) , 2)
wkNow= wkNow & Right("0" & Second(Now()) , 2)
'ErrorLog Filename
strErrorLog = Path & "Log\ErrorLog_" & wkNow & ".txt"
'Settings
MyBPOpt.CreateLogFile = true
MyBPOpt.LogFileName = Path & "Log\Log_" & wkNow & ".txt"
MyBPOpt.PrintingTimeout = 1000000000
MyBPOpt.BeforePrintingTimeout = 25000
MyBPOpt.KillProcessIfTimeout = 1
'loop through the folder and get the file names
For Each Fil In FLD.Files
On Error Resume Next
strFilename = strSourceFolder + "\" + Fil.Name
P2F.ConvertFile strFilename, strDestFolder + "\" + Fil.Name + ".swf",, MyBPOpt
IF Err.Number <> 0 THEN
Set myFSO = CreateObject("Scripting.FileSystemObject")
Set WriteStuff = FSO.OpenTextFile(strErrorLog, 8, True)
WriteStuff.WriteLine(strFilename & "," & FSO.GetFileName(strFilename) & "," & FSO.GetExtensionName(strFilename) & "," & Err.Description)
WriteStuff.Close
SET WriteStuff = NOTHING
END IF
Next