Relative Path problem

[inborntester]

Code:

TestDir=Environment.Value("TestDir")
TestNameLength=Len(Environment.Value("TestName"))
TestDir=Left(TestDir,Len(TestDir)-TestNameLength)
Set excel = CreateObject("Excel.Application")
InitFilePath=TestDir+"\Init\Init.xls"
Set workbook = excel.Workbooks.Open(InitFilePath)
Set worksheet=workbook.Worksheets("Sheet1")
Set url = worksheet.Cells.Find("url")
urladd= worksheet.Cells(url.row,(url.column)+1)
excel.Quit
SystemUtil.Run urladd

my test directory(folder) is "Test" and am having a folder named "Init" beside my test folder. there i am having a excel file "Init.xls" to store url of the application. i read it using the above code. the idea is, i have used the
predefined environment variable "TestDir" for my logic.