MATLAB: How to Convert vector elements to zero for certain N length when its values gets negative

Question

I have a column vector F= (0; 0; 0; 0; 5; 7; 12; 11; 23; 32; 22; 10; 8; -6 0; -8; 1; 4; 8; -5; 0; 0; 0; 6; 8; 9; 13; 14; 12; 23; 34; 22; 16; 17; 4; -5 ; -6; 5; 7; 0; 0; 0)

I want to convert values of F when it gets negative (in this case -6 and -5) till N (lets N=8)

so result would be F= (0; 0; 0; 0; 5; 7; 12; 11; 23; 32; 22; 10; 8; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 6; 8; 9; 13; 14; 12; 23; 34; 22; 16; 17; 4; 0; 0; 0; 0; 0; 0; 0) how to do this?

Answer 1

F(F<0 & F>=-8)=0