In Powershell, how do I match whole cell for Excel Find/FindNext?

I want to do Find and FindNext functions which match the entire contents of the cell.  I have these functions working but the default is to match any part of the cell contents which results in my getting too many matches.  I am trying to count how many times specific text appears in a column of data.

Below is just one of many attempts.  The "$find" line is the one that fails.  It fails with different errors depending on the parameters passed.  For example, if I pass it as shown below I get:

Error: exception calling 'find' with '4' arguments: Type mismatch exception 0x80020005

If I pass the parameters as: $amt,,,1

I get the syntax error: missing expression after ','

This link is the Microsoft description of this function:

http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel.range.find.ASPX

$xlsx  = "C:\users\me\TEST.xlsx"
write-host "Testing FIND for $xlsx" -fore cyan

$excel = new-object -comobject Excel.Application
$excel.Visible = $True
$xlb = $excel.Workbooks.Open($xlsx)
$xls = $xlb.Sheets.Item(1)

$range = $xls.range("C1").EntireColumn
$amt   = 9.9    
$whole = 1      
$find  = $range.find($amt,$null,$null,$whole)
if ($find)
  { write-host "FIND ok: $amt" -fore green
    $find2 = $range.findnext($find)
    if ($find.row -ne $find2.row)
      { write-host "FINDNEXT ok: $amt" -fore green }
    else
      { write-host "FINDNEXT - not found: $amt" -fore yellow }
  }
else
  { write-host "FIND - not found: $amt" -fore yellow }

$excel.quit()

Any ideas?  I'd prefer to keep it as Find/Findnext but am open to alternative ways to count the number of times a string occurs in a range.