@Attaullah Shah Dear Attaullah Shah,I use your latest command --asrol--,but if I run the command,I always get error.Do you know why?Thank you in advance.

Code:
. which asrol
/Applications/Stata/ado/plus/a/asrol.ado
*! Attaullah Shah; May 22, 2020 ;  Email: attaullah.shah@imsciences.edu.pk; Support website: www.Fi
> nTechProfessor.com
*! Version 5.1:  Sep 4, 2020 : Mutilple statistics / variables can used used now in the flexible wi
> ndow

webuse grunfeld
. bys company: asrol invest, stat(mean) win(year 4) 
variable invest_mean4_ not found
r(111);

. bys company: asrol invest, stat(mean) win(year 0 4) 
variable invest_mean0_4 not found
r(111);