Give LABKEY.Pipeline.getPipelineContainer() a try:
https://www.labkey.org/download/clientapi_docs/javascript-api/symbols/LABKEY.Pipeline.html#.getPipelineContainer
States that it gets the container in which the pipeline for this container is defined.
Running the following in firebug:
LABKEY.Pipeline.getPipelineContainer({
containerPath: 'home',
success: function(resp){ console.log(resp) },
failure: console.log
})
will output a resp object that contains:
{
containerPath: "/home",
webDavURL: "/labkey/_webdav/home/%40files/"
}
The webDavURL property is what you might be looking for (at least you can transform that string into what you need).
Cheers,
Anthony Corbett