Which incoming path required GetLocalPath activity

I have TFS 2013. I need convert path like ConvertWorkItem in tfs 2012. But Workspace doesn't exist in TFs2013 default definition. SO, I discovered, That instead this activity Microsoft created GetLocalPath activity. I try in incoming path set different value:

$/Project/Path/ or this way: ($PublishDir)/Path/

No one of this example doesn't work. In result it set same value, that was setup in incoming. In my case works only physical path in build agent, like this:

d:\BuildAgent\78\Path\

In this case I have two question:

1. Why need GetLocalPath Activity, If they doesn't convert path? In this case, I can setup path right in Execution Activity.
2. Maybe I set wrong value? I have many build agent in different servers, and I can't use one physical path in different server.

Try the following:

buildDetail.BuildServer.TeamProjectCollection.GetService(Of VersionControlServer).GetWorkspace(srcPath).Name