Here is the options for creating the string CT00 - I notice that you are using -3.5% crossfall (expressed as a drop of -0.0259 etc) so I am using 100/101 rather than 110.
110,MC00,,LC00,0.2759,0,,0,200
100,MC00,LC00,CT00,-0.035,0,,-0.74,200
101,MC00,LC00,CT00,-0.035,200,,-0.74,300,,-1.49
100,MC00,LC00,CT00,-0.035,300,,-1.49,500
Once CT00 is creted, design the outer string from it as normal
(once again, I prefer to use option 100 if I know the crossfall value, so -0.025 rather than -0.1875)