Shell Programming and Scripting

I wanted to use matrixs in awk and got some problem, here is some of the script code, from the BEGIN tag:
row_char[1]="a";row_char[2]="b";row_char[3]="c";row_char[4]="d";row_char[5]="e"$
row_char[8]="h";row_char[9]="i";row_char[10]="j";row_char[11]="k";
from the proccess passage:
sentence[varchar[11],1]=1;
diffrence=4;
i=7;
sum_index=diffrence+i;
printf("test: %d",sentence[row_char[11],1]); it prints that like it should be test: 1
printf("test2: %d",sentence[row_char[sum_index],1]); here it prints test2: 0 that does not right.
I almost sure the problem is the form of the array index ,as in awk probably there is no matrixs.
Please help me with this.

Can somebody help me?

Nobody answered to my question