Usando a Política de Grupo ou a política local da máquina, vá para
Computer Configuration ->
Administrative Templates ->
Windows Components ->
Event Log Service ->
[Application|Security|Setup|System]
E defina a configuração "Fazer backup do log automaticamente quando estiver cheio".
This policy setting controls Event Log behavior when the log file reaches its maximum size and takes effect only if the "Retain old events" policy setting is enabled.
If you enable this policy setting and the "Retain old events" policy setting is enabled, the Event Log file is automatically closed and renamed when it is full. A new file is then started.
If you disable this policy setting and the "Retain old events" policy setting is enabled, new events are discarded and old events are retained.
If you do not configure this policy setting and the "Retain old events" policy setting is enabled, new events are discarded and the old events are retained.
Depois, tudo o que o seu script precisa fazer é coletar periodicamente o diretório dos arquivos de log de eventos arquivados e transferi-los para o compartilhamento de rede.