Please explain why I'm getting a syntax error?

So I'm building up this Frankenstein VBA code project from snippets I'm finding online and I have this put together:

Dim unit As Long
Dim columncount As Long
columncount = Application.WorksheetFunction.CountA(1:1)
unit = 1

Do While (unit <= columncount)
Cells(38, unit + 1).Value = unit
unit = unit + 1
Loop

Now, when I run it with an actual number in "columncount = 250", it works fine. But when I change it to "columncount = Application.WorksheetFunction.CountA(1:1)", I get syntax error. What have I gotten wrong in there?
Also, I have tried "columncount = Application.WorksheetFunction.CountA("1:1")", but it only runs once through the loop and then quits.
Can someone please point out what the VBA newbie is missing?