SUBSTR(arg,position,n)
如：
a='(916)734-6281';
x=SUBSTR(a,2,3);

x='916'

试试kindex或kindexc函数

data school;
   length name $30.;
   input name $;
datalines;
HistoriansXiaoXue
BaYiZhongXue
YuminXiaoXue
101ZhongXue
RenDaFuZhong
ZhongguancunYiXiao
;run;

data PMSchool;
   set school;
   if prxmatch('/(XiaoXue|ZhongXue)/', name) then PMSchool = 1;
   else PMSchool=2;
run;