Use a band pass filter in frequency domain curves to reduce noise. Any filtering ideas

Hi,

I implement some modeling in Matlab and I would like first to reduce the noise in the middle of my frequency domain spectrum.

B=[762.305507316901 + 0.00000000000000i -148.857416270189 - 112.465123016362i 72.1040204690655 - 77.9737891434329i -24.1958898297061 + 14.9530490200792i -20.9643502688155 - 37.6539437989538i 8.21878228486253 - 16.6006804766844i -10.9777480800320 - 5.61246731621860i -6.05586452175864 - 15.9578896518838i -7.17169733754906 - 9.67871406760067i -4.49235338175438 - 11.4089004975904i -4.29055031400439 - 6.72051766892770i -7.74693504352472 - 7.54376577962856i -12.1840452596067 - 5.08535088203798i -6.06247642744580 - 1.69043070996695i -4.19928295196479 - 2.13636873817847i -0.490052001053044 - 5.32788376534700i -7.91090438445112 - 6.84309512949012i -5.00953492796304 - 2.11327589883362i -11.4128243232377 + 0.814558415615140i -3.95144744244225 + 0.783518113845253i -6.57826560301738 - 3.99839282643482i -1.04934916941096 - 1.36279865528096i -2.87456887445222 + 0.396625379683240i -2.87456887445222 - 0.396625379683240i -1.04934916941096 + 1.36279865528096i -6.57826560301738 + 3.99839282643482i -3.95144744244225 - 0.783518113845253i -11.4128243232377 - 0.814558415615140i -5.00953492796304 + 2.11327589883362i -7.91090438445112 + 6.84309512949012i -0.490052001053044 + 5.32788376534700i -4.19928295196479 + 2.13636873817847i -6.06247642744580 + 1.69043070996695i -12.1840452596067 + 5.08535088203798i -7.74693504352472 + 7.54376577962856i -4.29055031400439 + 6.72051766892770i -4.49235338175438 + 11.4089004975904i -7.17169733754906 + 9.67871406760067i -6.05586452175864 + 15.9578896518838i -10.9777480800320 + 5.61246731621860i 8.21878228486253 + 16.6006804766844i -20.9643502688155 + 37.6539437989538i -24.1958898297061 - 14.9530490200792i 72.1040204690655 + 77.9737891434329i -148.857416270189 + 112.465123016362i]

freq= 0:(4*pi)/178:pi;

If you plot(freq,B) you can see my curve. So, I would like to filter in 1/2 or 1/3 of the amplitude of the frequency components in middle frequencies B(14:33). Any ideas how to implement band-pass filtering?

Thank you,

G