Multiply rows with a value before adding.

Hi All,
Can anyone help me to get a best formula in completing my task.

I have few rows, the first row will have a value of 0 or 1 and its static other rows will have any numeric values
I need to multiply each row with the first row and finally sum the values in a cell

for example
A B C D D E F G H I...
Row 1 --- 1 0 1 0 1 0 0...n
Row 2 ---- 4 8 9 9 4 0 1..n
Row 3 ---- 5 6 7 8 7 6 5 4..n
Row 4---- 9 0 3 4 5 6 7 8..n

If know I can add something like

B1=C1*C2+D1*D2+E1*E2+F1*F2+G1*G2+H1*H2+I1*I2*J1*J2*K1*K2+L1*L2......
B2=C1*C3+D1*D3+E1*E3+F1*F3+G1*G3+H1*H3+I1*I3+J1*J3+K1*K3+L1*L3
B3=C1*C4+D1*D4+E1*E4+F1*F4+G1*G4+H1*H4+I1*I4+J1*J4+K1*K4+L1*L4

but I need to have this till end of the sheet. so the formula looks clumsy.
Is there any formula in excel to do perform this task without macros.

Thanks,
Ravi

Thankyou Glenn Kennedy, It worked perfect. Appreciate your quick response.