Hi im new to using equations on solidworks just wanting to know if it is possible to set the number of instances in a curve pattern with an equation or if there is a different way of doing the same thing.

i have to be able to adjust the height of a structure and as the height increases so does the number of cross members but i have to keep the distance from the top of the structure- the top of the first cross member the same also the distance from the bottom of the structure to the bottom of the last cross member must remain the same. 

thanks.  I am using the 2013 version.