I have a custom list of letters A-Z which enables me to type an 'a' in cell
E3 and drag down the fill handle to get the other characters. However, when
rows are hidden I would like to ignore hidden cells and re-alphabetize just
the visible cells.

I am able to do this with numbers with the following recorded macro:
Sub mcrRenumVisCells()
'Renumbers visible cells -- ignores hidden cells
Selection.SpecialCells(xlCellTypeVisible).Select
Selection.DataSeries Rowcol:=xlColumns, Type:=xlLinear, Date:=xlDay,
Step:=1, Trend:=False
End Sub

Is there anything I can do adapt this for my alphabets? Thanks.