The DDL operator cannot execute any SQL statements that return data (i.e. a RECORD parcel) back to the operator. However, I do not believe the COLLECT STATISTICS request actually returns data to the calling application.
If this is true, then yes you can use the DDL operator for this.
Which version of the DDL operator are you using? The use of the DDL operator was severely restricted, but we opened it up in TPT13.0 and then backshipped the support to TPT12.0 (with a patch).
If you are using a version of TPT prior to TPT12.0, then you will not be able to collect stats. If you are using TPT12.0, please make sure to get the latest patch for the DDL operator from the patch server.