In Text Speaker you can start reading from any position within a document.

To start reading open the document in Text Speaker, go to File >> Open. Select the document to read. Place the cursor to a location from where you want to start the reading. Go to the Speak menu and select the Speak from current cursor position option. Alternatively, you can select this option by right clicking on the document.

You can also set bookmark within the document for easy reference.
Adding bookmarks will help you to start reading document from that position whenever required.