how to execute a query that is assigned to a plsql variable

Hi All,

We are on 11.2.0.3 database on Windows 2008.I am working on a script to automatically create the datafile when there is an alert in the alertlog file to do so.

Below is an example of part of the sample code. I have the required query built in to the variable sql_text, but  dont know how to execute the query in that variable.

Even though the below output error is pointing at DECLARE as possible cause. I believe the issue is the execute... statement. As the code works well without the execute statement.

Please suggest how to execute the string/query in the variable. Thanks a lot.