Get a filename from a folder using a wildcard - excel

Question

I'm completely new to VBA and had some trouble googling this problem cause variable has multiple meanings.
I am trying to open a file and assign its name to a variable. The file's name is never the same though I always download it to the same folder (one file in that folder only). The only recognizable thing about the file are 3 letters "ABC".
So far I managed to get opening the file to work but not assigning the non-standardized file name to a variable.
Sub openwb()
Dim wb As Workbook Dim directory As String
directory = "D:\Users\AAA\Desktop\Practice"
Set FSO = CreateObject("Scripting.FileSystemObject")
Set folder = FSO.GetFolder(directory)
For Each file In folder.Files
If Mid(file.Name, InStrRev(file.Name, ".") + 1) = "xlsm" Then
Workbooks.Open directory & Application.PathSeparator & file.Name
End If
Next file
End Sub
Public Sub RecordFileName()
Dim sPath As String, sFile As String
Dim wb As Workbook
sPath = "D:\Users\AAA\Desktop\Practice"
sFile = sPath & "*ABC*"
End Sub

Answer 1

Here is a function you can use. It will return the filename you are looking for, and you can specify a file pattern if you want to, or you can omit that argument and it will assume all files.
Function GetFullFileName(sFolder As String, Optional sPattern As String = "*") As String
Dim sFile As String
' ensure sFolder ends with a backslash
If Right$(sFolder, 1) <> "\" Then sFolder = sFolder & "\"
sFile = Dir(sFolder & sPattern)
If sFile = "" Then
MsgBox "NOT FOUND: " & sFolder & sPattern
End
End If
GetFullFileName = sFolder & sFile
End Function
Usage:
MsgBox GetFullFileName("C:\Users\Fred\Documents")
Or
MsgBox GetFullFileName("C:\Users\Fred\Documents\", "*ABC*.xlsm")
Or
sFullFile = GetFullFileName("C:\Users\Fred\Documents\", "*ABC*.xlsm")