I think it's either going to be a manual effort (row by row) if you hate the
extra line within the cell for the rows that currently print ok.
One of the things that would concern me is that the paper copy may look fine on
my printer, but if I share it with others, it may not look fine for them.
If you decide to add that extra alt-enter to just the cells you want, you could
select the range first and use a macro to do the work.
Dim myCell As Range
Dim myRng As Range
Set myRng = Nothing
On Error Resume Next
Set myRng = Intersect(Selection, _
Selection.SpecialCells(xlCellTypeConstants, xlTextValues), _
On Error GoTo 0
If myRng Is Nothing Then
MsgBox "Try another selection!"
For Each myCell In myRng.Cells
If Right(myCell.Value, 1) = vbLf Then
'already there, so skip this cell
myCell.Value = myCell.Value & vbLf
If you're new to macros:
Debra Dalgleish has some notes how to implement macros here:
David McRitchie has an intro to macros:
Ron de Bruin's intro to macros:
(General, Regular and Standard modules all describe the same thing.)