This code should do it for you - goes into a regular code module.  Cut and
paste.
Use [Alt]+[F11] to open the VB Editor.  When you get there, from it's menu
choose Insert | Module.  Paste this code into the module and close the VB
Editor.  To do the work, use Tools | Macro | Macros and select and run the
MoveGroups macro.

Sub MoveGroups()
   'asks user for # of cells
   'from col. A to move into
   'other columns.  Each group
   'will be moved into individual
   'columns beginning with B
Dim ColPointer As Long
Dim TopRow As Long
Dim CellsToMove As Long
Dim LastRowWithData As Long
Dim sourceRng As Range
Dim destRng As Range

CellsToMove = InputBox$("How many rows in a group" _
& " from column A?", "Rows in a Group", 0)
If CellsToMove < 1 Then
   Exit Sub ' no work to do
End If
If Val(Left(Application.Version, 2)) < 12 Then
   'in pre-2007 Excel
   LastRowWithData = _
    Range("A" & Rows.Count).End(xlUp).Row
Else
   ' in Excel 2007 (or later)
   LastRowWithData = _
    Range("A" & Rows.CountLarge).End(xlUp).Row
End If

ColPointer = 1 ' initialize
TopRow = 1 ' initialize
Do Until TopRow > LastRowWithData
   Set sourceRng = _
    Range("A" & TopRow & ":" _
    & Range("A" & TopRow).Offset _
    (CellsToMove - 1, 0).Address)
   Set destRng = _
    Range(Range("A1").Offset(0, ColPointer).Address & _
    ":" & Range("A1").Offset(CellsToMove - 1, _
    ColPointer).Address)
   destRng.Value = sourceRng.Value
   sourceRng.Clear
   ' update pointers
   TopRow = TopRow + CellsToMove
   ColPointer = ColPointer + 1
Loop
End Sub