Again, the airports go at the *end of the sections, not at the beginning, and the initial departure point is at the end of the line. They have to be in the proper order. You also missed removing a / character.
AC#1001,N625AE,26%,4HR,IFR,19:58:50,21:18:49,320,F,3430,KDFW,21:49:34,22:44:56,240,F,3327,KLFT
and yes, this can be added as a new line in the AI traffic file.
This plane will depart KLFT at 58 minutes after the hour every 4 hours. Normally you would not use a starting time like 19:58 with a 4 hour plan, but instead something like 00:58, 01:58, 02:58 or 03:58. But I believe TTools will change that for you.