Loop and append

I am a total newbie when it comes to VBA and excel though, not to programming in general. It seems that I am having quite a time trying to decipher VBA. What I want to do, is loop through an unknown number of rows in a column and then if it contains a specific acronym it will check the same row ina different column it will append one of two strings depending on the second cell's contents. This code doesn't seem to work but perhaps it will help elucidate what I'm getting at.

Sub AppendMacro()
'
'Append Macro
'Keyboard Shortcut: Ctrl+l
'
Dim c As Range

For Each c In Range("S:S")

    If c.Value = "USAA" Or c.Value = "U.S.A.A" Then

    ActiveCell.Offset(0, 2).Select

     If ActiveCell.Value = "AM" Then

       ActiveCell.Value = ActiveCell.Value & "8-10"

       End If

    End If
Next c

End Sub

One thing I know is tht the value of the cell isn't exactly going to be USAA or U.S.A.A but will contain those sets of characters. Also, I'm pretty sure I'm misunderstanding how ActiveCell works

(Cross posted on stack overflow: http://stackoverflow.com/questions/6...oop-and-append)

Solved by GSerg over at Stack overflow:
"

]Dim c As Range
For Each c In Range("S:S").Cells
    If instr(c.Value, "USAA") > 0 Or instr(c.Value, "U.S.A.A") > 0 Then
        With c.Offset(0, 2)
            If .Value = "AM" then .Value = .Value & "8-10"
        End With
    End If
Next c

InStr finds first instance of a string inside another string.
ActiveCell is the currently selected cell in the active window, not the loop counter. It is advisable to avoid using ActiveCell (and .Select) in code, unless you actually want the user to select a cell and then act upon it.
With...End With is just a handy way to temporarily capture a reference to c.Offset(0, 2), to avoid explicit variable for it or calling it three times in a row. Without this block, it would be

If c.Offset(0, 2).Value = "AM" Then
    c.Offset(0, 2).Value = c.Offset(0, 2).Value & "8-10"
End If

"