Help reconstructing a Lanczos filter function?

Hi, Im going through old programs and ran into a problem. I build a function called lnz_co for lanczos filters but it has been erased from my library can someone help me out? the function sets up as follows:

[md,nd]=size(v); %%where v is a vector

fo=0; %% initial frequency

fc=1/48; %%cut off frequency

fn=1/2; %%Nyquist frequency

lp=200; %%not sure what this is

df=1/md;

f=lnz_co(fo,fc,fn,lp,df);

Please help