couch db replication behind http proxy with basic auth

is there a recommended way to replicate couch databases if the client is behind a http proxy with basic authentication?

We´re using couch 1.6.1 and replicating through replication documents. So I´m posting a replication document like this:

 {
 "continuous": true,
 "create_target": true,
 "proxy": "http://ProxyUsername:Password@proxyIP:13500",
 "source": "https://sourceuser:sourcepw@host.com/databasename",
 "target": "databasename",
 "owner": null,
 "user_ctx": {"roles": ["_admin"]}
 }

This is somehow working, but the username and password for the proxy is then visible in the _replicator database in plain text which is not really acceptable.

Is there a possiblity for the couchdb replication to use the operating system settings (for example on windows running as service)? (also it would be nice to cancel running replications and start new ones if the operating system settings change)

any advice is welcome.