How to start a data collector upon high CPU load condition?

I have a Windows 2008R2 server that experience high CPU load for several minutes about once every couple of weeks.

Unfortunately, when these events occurs, logging into the system through RDP or at the console takes so long that, when it's done, the problem is usually gone.

So, I've prepared a perfmon data collector that will capture the relevant data (CPU time per process, details of IIS worker processes, etc.) but I have no idea how to trigger it automatically under high-CPU load condition (as defined in Nagios: that's >99% CPU usage for more than 300 seconds).

Unfortunately, the low frequency of these events makes it difficult to let the data collector run on its own.

I have currently worked around it by using circular logging and leaving it running but that's not really a satisfactory solution.

So, is there a (simple) way to get that data collector started under these conditions ?