The easiest would be to use a User Defined Function or a macro.
Here's a UDF
Function ConCatRange(CellBlock As Range) As String
Dim cell As Range
Dim sbuf As String
For Each cell In CellBlock
If Len(cell.text) > 0 Then sbuf = sbuf & cell.text & ","
Next
ConCatRange = Left(sbuf, Len(sbuf) - 1)
End Function
=ConCatRange(C2:C45) enetered in F2
Returns a comma de-limited list.
Change the cell.text & "," to " " for a space or "" for no space.
If not familiar with VBA and macros, see David McRitchie's site for more on
"getting started".
http://www.mvps.org/dmcritchie/excel/getstarted.htm
In the meantime..........
To create a General Module, hit ALT + F11 to open the Visual Basic Editor.
Hit CRTL + R to open Project Explorer.
Find your workbook/project and select it.
Right-click and Insert>Module. Paste the above code in there. Save the
workbook and hit ALT + Q to return to Excel window.
Enter the formula as shown above.
Gord Dibben Excel MVP