First Cell In Range Not Searched

Range a1:iv1 (the entire top row), simply contains the column heading names A,B,C...AA,AB... IT,IU, IV (all possible 256 column names)

Range a2:iv2 contains the series of numbers 1 through 256

If you key in "B", the message box tells you "2"
If you key in "2", the message box tells you "B"

This is my own beginner's exercise.

The following code seems to work for everything except the very first cell in the range.

If I key in "A" the code returns 27, which is actually "AA".

If I key in "1" the code returns "J" (so it is finding the leading numeral 1 in 10).

The code is not searching the first cell in the range.

How may I modify this code to include the first cell (A1)?

Dim c As Range
 arg = Trim(TextBox1.Value)
 
 If IsNumeric(arg) Then


  With Worksheets(1).Range("a2:iv2")
   Set c = .Find(arg, LookIn:=xlValues)
   If Not c Is Nothing Then
    MsgBox "Column " & c.Offset(-1, 0).Value & " Is equal to " & TextBox1.Value
   Else
    MsgBox TextBox1.Value & " not found!"
   End If
  End With


 Else


  With Worksheets(1).Range("a1:iv1")
   Set c = .Find(TextBox1.Value, LookIn:=xlValues)
   If Not c Is Nothing Then
    MsgBox "Column " & TextBox1.Value & " is equal to " & c.Offset(1, 0).Value
   Else
    MsgBox TextBox1.Value & " not found1"
   End If
  End With
 End If
 TextBox1.Value = ""
 TextBox1.SetFocus

Re: First Cell In Range Not Searched

Thanks, Reafidy! Now it works like a charm. I did start out with the macro recorder, and played with the code for about an hour, but I was missing the concept of

With Worksheets(1).Range("a2:iv2")
Set c = .Find(...

which I subsequently found by searching ozgrid.com

That example code which I borrowed lacked all the arguments that you have provided.

I am trying to understand how each argument works, and especially, which arguments did the trick to make my code search the first cell in the range.

I searched in Excel Help, to read up in detail on what the find arguments might mean, but did not seem to find something useful.