Clearing Cell Values of a table if matching criteria - excel

Question

I am looking to sort through a specific range of cells and look to see if the LEN(gth) of that cell is equal to 20. If it is, I would like to clear the contents of said cell and move to the next until they are all evaluated.
I have this report that is pulled from a website and exported to excel and the annoyance is a 0.0% that shows up as pound signs (# x's 20). I've tried other macros that search for strings, it completely ignores 0%, the one constant is that each cell that this appears in is exactly 20 characters in length.
What should happen is that I am:
1 Searching C3:U20
2 for cell.len = 20
3 if activecell = matches criteria
4 then clear.contents
5 Goto 1 until all activecells with a len of 20 are cleared
Thank you for any assistance you can provide.
G
*EDIT*
Since I couldn't make that work, I used a "work around". It's inefficient as all blarp but since it's only used on a small table it doesn't really matter. I just have to do this in "three" seperate scripts. I found that if I converted the ranges from Percentage formatting to General, I could just look for the overflow number as a string. Then once they are "cleared" I just reconvert those columns to a percentage formatting:
Sub sub_ConvertToGeneral()
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''' Convert the Percentage Columns to General Format
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Columns("F:F").Select
'Application.FormulaBarHeight = 2
Range("F:F,H:H,L:M,O:O,S:S,U:U").Select
Range("U1").Activate
Selection.NumberFormat = "General"
'Selection.NumberFormat = "0.00%"
Range("A1:B1").Select
End Sub
Sub sub_Overflow()
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''' Find Overflow and delete every instance of it
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Dim FindString As String
Dim rng As Range
FindString = "2.6965E+308"
50
If Trim(FindString) <> "" Then
With Sheets("Main Import").Range("C1:U20")
Set rng = .Find(What:=FindString, _
After:=.Cells(.Cells.Count), _
LookIn:=xlValues, _
LookAt:=xlWhole, _
SearchOrder:=xlByRows, _
SearchDirection:=xlNext, _
MatchCase:=False)
If Not rng Is Nothing Then
Application.Goto rng, True
ActiveCell.ClearContents
Do
Set rng = .FindNext(rng)
GoTo 50
Loop While Not rng Is Nothing
Else
End If
End With
End If
Range("A1").Select
End Sub
Sub sub_ConvertToPercentage()
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''' Convert the General Columns to Percentage
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Columns("F:F").Select
'Application.FormulaBarHeight = 2
Range("F:F,H:H,L:L,O:O,S:S,U:U").Select
Range("U1").Activate
'Selection.NumberFormat = "General"
Selection.NumberFormat = "0.00%"
Range("A1:B1").Select
End Sub

Answer 1

If the cells to be cleared actually contain exactly 20 characters (So LEN(A1) would display 20), then Select the cells you want to examine and try:
Sub dural()
For Each r In Intersect(Selection, ActiveSheet.UsedRange)
If Len(r.Text) = 20 Then
r.Clear
End If
Next r
End Sub
EDIT#1:
This version will clear cells with a value greater than 1.0E+307:
Sub dural()
For Each r In Intersect(Selection, ActiveSheet.UsedRange)
If IsNumeric(r.Value) Then
If r.Value > 1E+307 Then
r.Clear
End If
End If
Next r
End Sub