[Therion] survey of survey

Hi, Sorry for bothering you every day, today's question is : I have a toto.th file : survey toto -title “Toto" input toto_old.th input toto_new.th centerline equate 1.15@toto_old 1.3@toto_new endcenterline endsurvey Since I’m merging an old survey with a new one, I have stations from both surveys that are in the same scrap, in the toto-1p.th2 file I use: point 1271.69 1802.81 station -name 1.8@toto_old.toto But when I compile I have the following error : therion: error — toto-1p.th2 [10] -- survey does not exist -- toto_old.toto -- station does not exist -- 1.8@toto_old.toto What the heck am I missing ? Phil