Beamforming but only for total power?
I am not sure regarding total power but you can certenly focuse on ccertain frequencies of interest. 

Beamforming is a process in which different channels (a number of microphones for example) gather their information to cancel the uncorrelated component between them. Let $y(f)=[Y_1, Y_2, \ldots, Y_M]^T$ be signals received from $M$ channels S.T. $y(f)=x(f)+v(f)$, where $v(f)$ is noise. We construct:

$$Z(f)=\sum_{m=1}^{M}H^*_m(f)Y_m(f)=X_d(f)+V_r(f)$$

Where $X_d$ is our reconstructed desired signal and $V_r$ is the residual noise. Given a directional beam $d(f,cos\theta_d)=[1,e^{-j2\pi f\tau_0\cos\theta},\ldots,e^{-j2(M-1)\pi f\tau_0\cos\theta}]^T$, the white noise gain (WNG) of such a filter is given by:
$$\mathcal{W}[h(f)]=\frac{|h^H(f)d(f,cos\theta_d)|^2}{h^H(f)h(f)}$$
Note that all of these are functions of $f$, meaning they can be applied in only a single or couple of specific frequencies of interest. 

To find such a filter, simply solve for the maximum on $\mathcal{W}[h(f)]$ (the higher WNG is the better you reconstruction of the signal is) which yields the common delay and sum beamformer:

$$h_{DS}(f,cos\theta_d)=\frac{d(f,cos\theta_d)}{M}$$

There are many types of beamformers that can be produced such as the maximum directivity factor (DF) beamformer. I find this book is a good source. All of them can be applied as a function of $f$.