Adding a staff to just one line

Hi everyone.
I am trying to add a staff to only one line in my score under the first violins (I have two parts, first and second violin). However, whenever I add a staff for one instrument by going to the Instruments section, it always adds a staff to every line in the score, instead of doing only one line. Although I can hide the bars that have no notation in them, it leaves a large gap between my two instruments, which annoys me quite a lot. Do you have any way to add a staff to a single line without leaving a large gap between my two main lines for the rest of the score?
Any help is greatly appreciated.