The ModuleConfiguration property of PortalModuleBase from which your module inherits provides two properties of type string:
Me.ModuleConfiguration.ContainerPath - returns the relative path (including ApplicationName) to the container's folder
Me.ModuleConfiguration.ContainerSrc - returns the relative path (including ApplicationName) to the container's folder and the filename of the container
Also, if you need to obtain a reference to the actual container control you can use the following:
Dim ctnr As System.Web.UI.UserControl = CType(Me.ContainerControl, System.Web.UI.UserControl)