Laba diena,
Jau visus variantus išmėginau ir nežinau kaip teisingai užbaigti paiešką, 
kad nemestų klaidos "Run-time error 91: Object or variable with not set". 
Excelis 2000.
Kodas toks:

Dim c As Range
With Sheets("Sheet1").Range("a1:a6")
    Set c = .Find("*5*", After:=Range("A1"), LookIn:=xlValues)
    If Not c Is Nothing Then
        FirstAddress = c.Address
        MsgBox FirstAddress
        Do
            c.Value = 4
            Set c = .FindNext(c)
            If c Is Nothing and c.Address <> FirstAddress Then Exit Do
            MsgBox c
        Loop ' While Not c Is Nothing ' And c.Address <> FirstAddress
    End If
End With