create visual basic code on excel 2010

Hello,

I am new to VBA.I need to create a connection to database{oracle} and excute query.
I have opened the vba editor in excel 2010.
I tried typing some code in it

Sub Macro1()
 
Dim cnn As New ADODB.Connection
Dim rs As New ADODB.Recordset
 
cnn.ConnectionString = "Driver={Microsoft ODBC for Oracle}; " & _
"Server=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=yourHost)(PORT=yourPort)))(CONNECT_DATA=(SERVICE_NAME=yourServicename)(SERVER=DEDICATED)));User Id=yourUser;Password=yourPwd;"
 
cnn.Open
Set rs = cnn.Execute("select count(*) cnt from my_table")
 
Debug.Print rs("cnt").Value
 
cnn.Close
 
End Sub

It fails at Dim cnn As New ADODB.Connection , saying user defiend type not found.

Please suggest how to proceed.