Experimente a seguinte macro pequena:
Sub BuildList()
Dim N As Long, M As Long
Dim i As Long, s1 As String, s2 As String
N = Cells(Rows.Count, "A").End(xlUp).Row
M = Cells(Rows.Count, "B").End(xlUp).Row
ReDim wordlist(1 To N) As String
For i = 1 To N
wordlist(i) = Cells(i, 1)
Next i
For i = 1 To M
ary = Split(Cells(i, "B"), " ")
For j = LBound(ary) To UBound(ary)
For k = 1 To N
If wordlist(k) = ary(j) Then
Cells(i, "C") = Cells(i, "C") & " " & wordlist(k)
End If
Next k
Next j
Next i
End Sub