VBA find

Hi everyone.
Wondering if any one can help. The following code below is used in a large excel spreadsheet with a ton of numbers. in the top row (1) are reference numbers which at this preliminary stage in my coding I am just trying to find. (the reference numbers are in the sheet like this ex. 100,040 I hope the comma is not a big deal)

Code:
Sub ref()

Dim RefNumber As Long
Dim RefFound As Range
RefNumber = Application.InputBox("Reference #", "Meter Point Reference_ Number", , , , , , 4)

Set RefFound = Cells.Find(what:=RefNumber, *REALLY DONT KNOW WHAT_ TO PUT HERE", LookIn:=xlValues, LookAt:=xlPart, SearchOrder:=xlByRows,_ SearchDirection:=xlNext)

MsgBox "Found Reference # at column" & RefFound.Column

End Sub

I had gotten it to run but for every reference number I tried it gave me a column of 238 (even when i changed the reference number to a different corresponding column). Any help would be greatly appreciated.

[For those wondering my goal is: find reference number, find last row with data in the column, copy range, paste into new sheet.]