How do I find the file path from a namespace.class name?

I'm programatically looking ito a .aspx file and getting the file class name declared in its CodeBehind. For example, when analyzing myFile.aspx I read in its Page Directive and found its CodeBehind equals "myApplication\myPage.aspx.vb". Then I use the code below:
 
Dim Assm As System.Reflection.Assembly = System.Reflection.Assembly.LoadFrom("myApplication\bin\myApplication.dll") Dim ClassType As Type = Assm.GetType("myApplication\myPage.aspx.vb") ' myBaseType = "myApplication.Forms.BasePage" Dim myBaseType As System.Type = ClassType.BaseType  
Now I want to read the BaseFile (class = myApplication.Forms.BasePage). However, to read in this file, I need I need to get its full path instead of its namespace.class hiearchy. In this case, the BasePage is wrapped in a different namespace declaration thus I cannot just change the '.' to '\' in ord ...