comparing/copying largest files to new folder - vbscript

Question

What I wish to do is:
Copy files from a variety of sub-folders under a single main folder to a destination folder.
Three options when copying:
If no file in destination folder exists then copy.
If file exists, copy over if filesize is larger than destination file.
If file exists and both are the same filesize compare date/time and copy over if most recent.
Here is my pseudocode so far:
Dim filesys, strSourceFile, strDestFolder, strDestFile
Set filesys = CreateObject("Scripting.FileSystemObject")
strSourceFile = S:\SoCal\Section_2\*\Autogen\texture\*.agn
strDestFolder = F:\ADDON_SCENERY\simwestSOCAL\texture
strDestFile = F:\ADDON_SCENERY\simwestSOCAL\texture\*.agn
COPY each file in strSourceFolder
If IsEmpty (SourceFile, DestFolder)
Else If (SourceFile FileSize > DestFile)
Else If (SourceFile DateTime > DestFile DateTime)
Then 'keep/copy most recent file
End if
Am I on the right track?
Do I need to add a Loop?
Can one compare file sizes? All my research has found nothing yet on this.
Can I compare Date and Time against files?
As an update to my original post... (hope I am following forum rules correctly),
I have spent the last several weeks non-stop just reading-reading-reading and testing-failure-testing. I am happy to say (and a little proud), that I have completed my very first script... and it appears to work as planned but for just one file. I now need to convert this to work on all files inside my 'sourcefolder'.
I am a bit "brain dead" from this so any direction on converting this would be most appreciated. I know I need loops but what type and where? Do I rename everything referring to a file to a folder or use '*.txt' for files? In the meantime I will keep studying.
Here is my script (yea, lot's of MsgBox's so I could follow along the script path):
dim dFolder
dFolder = "S:\Scripting Workfolder\destfolder\"
dim dFile
dFile= "S:\Scripting Workfolder\destfolder\File 1.txt"
dim sFile
sFile = "S:\Scripting Workfolder\sourcefolder\File 1.txt"
Set fso = CreateObject("Scripting.FileSystemObject")
'Check to see if the file already exists in the destination folder
If Not fso.FileExists(dFile) Then
MsgBox "File does not exist - will copy over to dFolder"
fso.CopyFile sFile, dFolder, true
Elseif fso.FileExists(dFile) Then
MsgBox "File already exist in destination folder determine largest"
ReplaceIfLarger sFile, dFile
End If
Sub ReplaceIfLarger(sFile, dFile)
const overwrite_existing = true
dim objFSO
set objFSO = createobject("Scripting.FileSystemObject")
dim objSourceFile
set objSourceFile = objFSO.GetFile(sFile)
'dim kbSourceSize
kbSourceSize = objSourceFile.size
dim objTargetFile
set objTargetFile = objFSO.GetFile (dFile)
'dim kbTargetSize
kbTargetSize = objTargetFile.size
If kbSourceSize > kbTargetSize Then
MsgBox "Source file is LARGER and will overwrite to dest folder"
objFSO.CopyFile objSourceFile.Path, objTargetFile.Path, overwrite_existing
ElseIf kbSourceSize < kbTargetSize Then
MsgBox "Source file is smaller - Will not overwrite to dest folder"
Else
ReplaceIfNewer sFile, dFile
End If
End Sub
Sub ReplaceIfNewer(sFile, dFile)
MsgBox "Both files exist and are the same size. Keep newest file"
const overwrite_existing = true
dim objFSO
set objFSO = createobject("Scripting.FileSystemObject")
dim dtmSourceFile
set dtmSourceFile = objFSO.GetFile(sFile)
dim dtmTargetFile
set dtmTargetFile = objFSO.GetFile(dFile)
If (dtmSourceFile.DateLastModified > dtmTargetFile.DateLastModified) then
MsgBox "Source File is Newer than Target File - Overwrite Target file"
objFSO.CopyFile dtmSourceFile.Path, dtmTargetFile.Path, overwrite_existing
Else
MsgBox "Source File is Older than Target File - Will not overwrite file"
End If
End Sub