Finding and storing an address of a cell with value<=x - vba

Question

I was wondering if someone would be kind enough to suggest some corrections to the indicated line in the script below.
It is throwing up "Object variable or With block variable not set" alarm.
I can only guess this means the "CellFound" range is not being set and that the problem lies within that line.
The "CellFound" variable is meant to find and store the location of a cell.value<=25 within DateRng for use by the following condition
To re-iterate, the entire script is to carry out the following tasks:
Locate a range that is located between 2 cells containing specific strings (DateRng)
Loop within this range for cells (i) that have a value <=25
Compare two other cells which are offset to "i"
Export a range of rows centered around "i" to different sheets pending the outcome of the above condition.
Thanks for your time.
Sub ReportCells()
Dim LR As Long, i As Long
Dim j, k As Long
Dim StartDate, FinishDate As String
Dim Sh As Worksheet: Set Sh = Sheets("Full chart and primary cals")
Dim CellFound As Range
'Range Extraction Script
'Search location and values
LookupColumn = "B"
StartDate = "2013.01.02 20:00"
FinishDate = "2013.01.09 20:00"
'Find Lower Limit
For j = 1 To 30000
If Sh.Range(LookupColumn & j).Value = FinishDate Then FinishDateRow = j
Next j
'Find Upper Limit
For k = FinishDateRow To 1 Step -1
If Sh.Range(LookupColumn & k).Value = StartDate Then StartDateRow = k - 1
Next k
'Set Range once located
Dim DateRng As Range: Set DateRng = Sh.Range(LookupColumn & StartDateRow & ":" & LookupColumn & FinishDateRow)
MsgBox DateRng.Address
'Find Cell
With DateRng
LR = Range("B" & Rows.Count).End(xlUp).Row
For i = 1 To LR
** Set CellFound = .Find(Sh.Range("M:M").Value <= 25, LookIn:=xlValues) **
MsgBox CellFound.Address
If Not CellFound Is Nothing And CellFound.Offset(0, -5).Value < CellFound.Offset(-1, -5).Value Then .Offset(-3, 0).Resize(10, 1).EntireRow.Copy Destination:=Sheets("DownT").Range("A" & Rows.Count).End(xlUp).Offset(2)
If Not CellFound Is Nothing And CellFound.Offset(0, -5).Value > CellFound.Offset(-1, -5).Value Then .Offset(-3, 0).Resize(10, 1).EntireRow.Copy Destination:=Sheets("UpT").Range("A" & Rows.Count).End(xlUp).Offset(2)
Next i
End With
End Sub
EDIT: The cell selection and copy block has been modified to the code below. It seems that the value<=25 set range commands are not executing as they should be. They are definately filtering data but on what column I am not sure. The block is returning a range of cells of the correct size. But only one range (instead of around 20 or so). And of the wrong range of rows :S I guess any progress is progress regardless of if it's right or wrong
With Sheets("Full chart and primary cals")
LR = Range("B" & Rows.Count).End(xlUp).Row
'For i = Range("M" & Rows.Count).End(xlUp).Row To 1 Step -1
For i = 1 To LR
With DateRng.Range("M" & i)
If Range("M" & i).Value <= 25 Then Set CellFound = Sh.Range("M" & i)
If Not CellFound Is Nothing Then .Offset(-5, 0).Resize(10, 1).EntireRow.Copy Destination:=Sheets("DownT").Range("A" & Rows.Count).End(xlUp).Offset(2)
End With
Next i
End With

Answer 1

The solution to the problem........
'Loop through sheet looking for cells
LR = .Range("B" & Rows.Count).End(xlUp).Row
For i = 10 To LR
'Find cells in "M" and store thier reference in Cellref
If .Range("M" & i).Value <= 25 Then Set Cellref = .Range("M" & i) Else Set Cellref = .Range("Z15")
'Find if Cell ref is contained within DateRange and store result as bool
If Not Application.Intersect(DateRange, Cellref) Is Nothing Then iSect = True Else iSect = False
'Output cell ranges to the appropriate sheets
If iSect = True And Cellref.Offset(0, -5) < Cellref.Offset(-10, -5) Then _
Cellref.Offset(-3, 0).Resize(10, 1).EntireRow.Copy Destination:=Sheets("DownT").Range("A" & Rows.Count).End(xlUp).Offset(2)
If iSect = True And Cellref.Offset(0, -5) > Cellref.Offset(-10, -5) Then _
Cellref.Offset(-3, 0).Resize(10, 1).EntireRow.Copy Destination:=Sheets("UpT").Range("A" & Rows.Count).End(xlUp).Offset(2)
Next i

Answer 2

From what I can tell from your code you're misusing the Range.Find() function, which will most probably cause it to return Nothing instead of a meaningful range.
Sh.Range("M:M").Value will throw a Type Mismatch error as you cannot use the .Value property of a Range containing multiple cells. As this error is contained within the arguments of your .Find function it's entirely possibly it's just being ignored but it will still cause .Find to return Nothing.
Even were that not the case Sh.Range("A1") <= 25 evaluates to either True or False (Depending on the value of A1) and the Find function would then search DateRng for the first instance of True or False within that range.
I'd recommend some further reading on how the Range.Find function works as it may not be suitable for the task you have in mind.