My equation calculates an interest rate

A1*C1^B1 + A2*C1^B2 + ... + A11*C1^B11 = D1

Columns A, B and D are given. The only unknown is C1 which I want to solve
for. I can do this using solver but I would like something that updates when
columns B and D change.

Can I do this without using the solver or have the solver automatically
update?

Thanks,
G