SAS function: count the occurrance of a character

data test;
input transfer_matrix $20.;
cards;
..0000000
11111111..
11000000001
1111111
111111111..
1111111000
0000.110
;
run;

data test;
set test;
count_1=countc(transfer_matrix,'1');
run;

proc print;
run;

Thanks, K.