Let us presume that the variable strConnect contains a valid ConnectionString
for your data. Then the following code should give you the intended result.
Private Sub Command1_Click()
Dim catMine As New ADOX.Catalog
Dim colAny As ADOX.Column
catMine.ActiveConnection = strConnect
For Each colAny In catMine.Tables("Customers").Columns
Print colAny.Name
Next colAny
End Sub