How to perform FORCITE geometry optimization of only one frame from multiple frames.

Dear All,

After building 3D amorphous cells, the .xtd file has multiple frames. 
In my case, I choose the structure with lowest energy for further simulation.
In case of DISCOVER, after displaying the frame that I want for geometry optimization(or energy minimization in DISCOVER), if I perform energy minimization, I can obtain the .xsd file from the selected frame.
But, FORCITE calculates all the frames and generates the .xtd file.

For example, if I build 3D amorphous cell of polymers having 5 frames, DISCOVER energy minimization task generates only one structure from the selected frame but FORCITE generates 5 frames.

Since one amorphous cell in my cacluation has many molecules, geometry optimization of all the generated frames of Amorphous cell takes too much time.

Recent version MS2016 does not have Discover module anymore.
So, please give me the information how to  perform FORCITE geometry optimization of only one frame from multiple frames. 

Thanks in advance!