Collate several files, each housed in separate folders, into a single folder - excel

Question

I need to copy 20+ files, each housed by unique folders, into a single folder. I know this should be fairly simple. I've created the below code but I keep getting a Compile Error: Object required error box. The below code looks sound to me so I'm really struggling to find where the error is.
Folder name is the date of the report (eg. 090118), hence, I decided to use a loop until the end of the month (931). I also added an error handling code so we can skip the holidays and weekends.
Sub CopyFiles()
Dim NewFolder As String
Dim NDay As Long
Dim FileName As String
Dim Month As Variant
Month = InputBox("Enter month, eg. 01-January")
NewFolder = "C:\Results\Trading\2018\" & Month & "\Backtest Daily Files\Daily GS\" 'Don't forget to edit this
NDay = 901
On Error Resume Next
Do While NDay < 931
FileName = Dir("C:\Reports\2018\" & Month & "\0" & NDay & "18\GS_Futures*.cs*")
FileCopy FileName, NewFolder
NDay = NDay + 1
Loop
End Sub

Answer 1

Dir doesn't return the full path. It either returns the file name only if found or a zero-length string if not found. If you want a definitive path and file name reference then you need to prefix the returned string with the folder.
An example would be,
...
Do While NDay < 931
FileName = Dir("C:\Reports\2018\" & Month & "\0" & NDay & "18\GS_Futures*.cs*")
if cbool(len(filename)) then _
FileCopy "C:\Reports\2018\" & Month & "\0" & NDay & "18\" & FileName, NewFolder
NDay = NDay + 1
loop
...
Seems to me that it would be easier to perform a recursive folder search within C:\Reports\2018\ but that's just MO. Relying on a user to type static input like 01-January unerringly is folly.

Answer 2

Found a solution. Needs some tweaking, but I'm all set for now. Thank you to all who took the effort to help. The problem was that I wasn't giving a file name to the destination just the folder (no .csv).
Sub CopyFiles()
Dim NewFolder As String
Dim NDay As Long
Dim FileName As String
Dim Month As String
Month = InputBox("Enter month, eg. 01-January")
NDay = 901
On Error Resume Next
Do While NDay < 931
FileName = "M:\MRL\2018\" & Month & "\0" & NDay & "18\GS_Futures_0" & NDay & "18.csv"
NewFolder = "M:\RMC reports\Trading\2018\" & Month & "\Backtest Daily Files\Daily GS\GS_Futures_0" & NDay & "18.csv"
FileCopy FileName, NewFolder
NDay = NDay + 1
Loop
End Sub
...