Go to the Subtitle Room, add blank subtitles along the timeline. There will have to be one subtitle for each line of text in the text file. Then import the text file. Each line of text will go to a separate subtitle.
Gateway DX4380, AMD A8-5500 Quad Core 3.2GHz with ATI Radeon HD 7560D; 16GB RAM; 1 TB SATA 7200 RPM; Windows 8 Pro 64-bit; PDR11, PDVD12.