I would like to be able to leverage the power of workflow web services (to make it easier for the client to make changes down the road using the http web request) but I'm stymied by one thing.

The authentication scheme used by the service they are trying to connect to has a password component that contains a hash that changes based on GMT. When I'm configuring Authentication there isn't a way to pass in a token for that (I've created a simple script that generates that without issue and manually tested it). 

Is there any way to access that on the fly and change that saved password?