I found solution but with VB. Insert code in normal module:
Function ExtractCap(Rng As Range)
Application.Volatile
ExtractCap = ""
For f = 1 To Len(Rng)
If Asc(Mid(Rng.Value, f, 1)) >= 65 And Asc(Mid(Rng.Value, f, 1)) <= 90 Then
ExtractCap = ExtractCap & Mid(Rng.Value, f, 1)
End If
Next f
End Function
And then use a formula such as this :
=ExtractCap(A1)
to show just the capital letters in A1.
Reference: http://www.mrexcel.com/forum/excel-questions/230646-extract-capital-letters-text-cell.html#post1127820