Code:
Set con=createobject("oledb.connection") con.open "Driver={Microsoft ODBC for Oracle};Server=; Uid=your_username;Pwd=your_password;"
OR
Check ODBC driver is available.
If not able to do DSN then Go to environmental variable and then set path
Code:
ConnectionString = "Provider=OraOLEDB.Oracle;Data Source="&mysource&";User Id="&user&";Password="&password&";"