Code:
int M[100];
int MU[100];
void MULVAL()
{
M[0]=AxB(A,N[0]%10);
M[1]=AxB(A,(N[0]%100-N[0]%10)/10)+((M[0]%100-M[0]%10)/10);
M[2]=AxB(A,(N[0]%1000-N[0]%100)/100)+((M[1]%100-M[1]%10)/10);MU[0]=(M[2]%100*100)+(M[1]%10*10)+M[0]%10;M[2]=(M[2]%100-M[2]%10)/10;
M[3]=AxB(A,N[1]%10)+M[2];
M[4]=AxB(A,(N[1]%100-N[1]%10)/10)+((M[3]%100-M[3]%10)/10);
M[5]=AxB(A,(N[1]%1000-N[1]%100)/100)+((M[4]%100-M[4]%10)/10);MU[1]=(M[5]%100*100)+(M[4]%10*10)+M[3]%10;M[5]=(M[5]%100-M[5]%10)/10;
M[6]=AxB(A,(N[2]%10))+M[5];
M[7]=AxB(A,(N[2]%100-N[2]%10)/10)+((M[6]%100-M[6]%10)/10);
M[8]=AxB(A,(N[2]%1000-N[2]%100)/100)+((M[7]%100-M[7]%10)/10);MU[2]=(M[8]%100*100)+(M[7]%10*10)+M[6]%10;M[8]=(M[8]%100-M[8]%10)/10;
M[9]=AxB(A,(N[3]%10))+M[8];
M[10]=AxB(A,(N[3]%100-N[3]%10)/10)+((M[9]%100-M[9]%10)/10);
M[11]=AxB(A,(N[3]%1000-N[3]%100)/100)+((M[10]%100-M[10]%10)/10);MU[3]=(M[11]%100*100)+(M[10]%10*10)+M[9]%10;M[11]=(M[11]%100-M[11]%10)/10;
M[12]=AxB(A,(N[4]%10))+M[11];
M[13]=AxB(A,(N[4]%100-N[4]%10)/10)+((M[12]%100-M[12]%10)/10);
M[14]=AxB(A,(N[4]%1000-N[4]%100)/100)+((M[13]%100-M[13]%10)/10);MU[4]=(M[14]%100*100)+(M[13]%10*10)+M[12]%10;M[14]=(M[14]%100-M[14]%10)/10;
M[15]=AxB(A,(N[5]%10))+M[14];
M[16]=AxB(A,(N[5]%100-N[5]%10)/10)+((M[15]%100-M[15]%10)/10);
M[17]=AxB(A,(N[5]%1000-N[5]%100)/100)+((M[16]%100-M[16]%10)/10);MU[5]=(M[17]%100*100)+(M[16]%10*10)+M[15]%10;M[17]=(M[17]%100-M[17]%10)/10;
M[18]=AxB(A,(N[6]%10))+M[17];
M[19]=AxB(A,(N[6]%100-N[6]%10)/10)+((M[18]%100-M[18]%10)/10);
M[20]=AxB(A,(N[6]%1000-N[6]%100)/100)+((M[19]%100-M[19]%10)/10);MU[6]=(M[20]%100*100)+(M[19]%10*10)+M[18]%10;M[20]=(M[20]%100-M[20]%10)/10;
}
Here's an add-on for the calculator script that does the multiplication. You'd have to integrate it yourself, and thus far only does 1 digit multiplied by 20 digits. You could go power genius on this and use those other conversion scripts already included to make it do more.