Sharepoint workflow and wait for external event?

In sp workflows, I use to subscribe for events, but all of them are sharepoint related. Is there any way to subscribe to external events ?

开发者_C百科In my case, I have to start a job on an external web application (no relation with SP) and wait for its completion (several minutes later) before resuming the workflow.

What is the best way to reach my goal ? Can I use standard workflow foundation external events in sharepoint (and in this case, where can I register my external system?) ?

PS: I'm also the builder of the external application (at least in this case), so I can adapt this application if needed.

thx

I discover lately that the pluggable workflow service is designed for such tasks.