[Nick Baradar]

Okay, I forgot about the behavior of locals that follow a backslash. You need double backslashes or a forward slash.

global Announcements "C:\Users\user\Announcements data"
global Final_data "C:\Users\user\Final data"

import excel "$Announcements\1.xls", sheet("Screening") cellrange(A8:O10008) firstrow clear
gen file=1
save Announcements_merged, replace
forval i=2/86{
import excel "$Announcements/`i'.xls", sheet("Screening") cellrange(A8:O10008) firstrow clear
append using "$Final_data\Announcements_merged"
replace file=`i' if missing(file)
save "$Final_data\Announcements_merged", replace
}

use "$Final_data\Announcements_merged", clear

sort file

Hello Andrew, thank you very much for your support! I made a small change in your code and it worked out, the entire effective code was:

global Announcements "C:\Users\user\Announcements data"
global Final_data "C:\Users\user\Final data"

import excel "$Announcements\1.xls", sheet("Screening") cellrange(A8:O10008) firstrow clear
gen file=1
save "$Final_data\Announcements_merged", replace
forval i=2/86{
          import excel "$Announcements/`i'.xls", sheet("Screening") cellrange(A8:O10008) firstrow clear
          append using "$Final_data\Announcements_merged"
          replace file=`i' if missing(file)
          save "$Final_data\Announcements_merged", replace
}


use "$Final_data\Announcements_merged", clear
sort file