Images float over the worksheet--they aren't contained in the cell.

You could put the pictures over each cell or you could put the pictures in a
comment associated with that cell.

This should work if your pictures are all in the same folder and have an
extension of JPG.

Option Explicit
Sub testme()
   Dim iCtr As Long
   Dim myPath As String
   Dim TestStr As String
   Dim myPict As Picture
   Dim myPictName As String

   'change to the correct location of the picture files    
   myPath = "c:\my pictures\test\"
   If Right(myPath, 1) <> "\" Then
       myPath = myPath & "\"
   End If
   
   With Worksheets("Sheet1")
       .Pictures.Delete 'remove any existing pictures???
       For iCtr = 1 To 2 '171 when you've finished testing!
           myPictName = myPath & iCtr & ".jpg"
           TestStr = ""
           On Error Resume Next
           TestStr = Dir(myPictName)
           On Error GoTo 0
           If TestStr = "" Then
               MsgBox "Picture: " & myPictName & " wasn't found"
           Else
               Set myPict = .Pictures.Insert(myPictName)
               With .Cells(iCtr, "C")
                   myPict.Top = .Top
                   myPict.Width = .Width
                   myPict.Height = .Height
                   myPict.Left = .Left
                   myPict.Placement = xlMoveAndSize
                   myPict.Name = "Pict_" & .Address(0, 0)
               End With
           End If
       Next iCtr
   End With
End Sub

If you're new to macros, you may want to read David McRitchie's intro at:
http://www.mvps.org/dmcritchie/excel/getstarted.htm