I would recommend that you place the csv file in the same folder as the template since one is only useful with the other. Then you can use the location of the template to get the folder name.
Code:
ThisDocument.Path & Application.PathSeparator & "Roster.csv"
If you desperately want to store the csv in the Documents path and not relative to the template then you can try this method
Code:
Dim wshShell As Object, sDocPath As String
Set wshShell = CreateObject("WScript.Shell")
sDocPath = wshShell.SpecialFolders("MyDocuments") & Application.PathSeparator & "Roster.csv"