Power Geopak-DTM Load

Hello and Happy New Year!!!

I am using Power Geopak v8i SS4.

I have a dtm file but my notes for how to import or convert this file to import are no longer applicable with the upgraded Geopak from SS2.  My notes refer to a Terrain menu item but I do not have this.  My issue is: I have a client supplied dtm file, I need to be able to import the tin and contours from this file but to Load DTM Features only gives tin, dat, and lattice file formatted input.  Can someone please help, I appreciate any thoughts or guidance you can provide on this topic.