user defined vector variable

Hello,
I would like to have create a vector (myVec) and be able to call individual values in an input script

Something like the following.
variable myVec (I have No Idea) [1,6,2,8,4,7]

variable singleVec equal ${myVec[2]}

I see that we can input an environmental variable and use it in the liggghts script but I would like to keep it contained in an input script.

any idea?