Hello, I am getting an invalid syntax error when I am try the following: I want ci to be summed only if n values are from the local i025. Could someone point me in the right direction on how to call for this variable?

local numst=42
local i025=floor(0.025*(`numst'-1))
local i975=ceil(0.975*(`numst'-1))
local i05=floor(0.050*(`numst'-1))
local i95=ceil(0.950*(`numst'-1))

quietly sum alpha
display as text "Difference in Differences coefficient=" as result _newline(2) r(mean)

sort asim
sum ci if _n==`i025'