"He who marches out of step hears another drum." ~ Ken Kesey
what I would do is copy the text, turn the text black and into an RGB jpg with a transparent background. take it into photopaint and use the effects>texture>plastic and find the settings that work best. invert the image and use the curves to adjust the gray to white so that only your highlights are black. Bring it back into corel and up the dpi to 600 and then convert it to a black and white jpg with halftone settings, or you can use the Advanced Artist tool for making a monochrome bitmapI hope this isn't confusing.
Mark can you detail exactly what the specs are you need.What color shirt are you printing and what colors inks are you going to use.With this info I think I can give you a much better solution to this.