help with hadamard matrix

i have Hadamard matrix

N=8;
H=hadamard(N)
>>H =

     1     1     1     1     1     1     1     1
     1    -1     1    -1     1    -1     1    -1
     1     1    -1    -1     1     1    -1    -1
     1    -1    -1     1     1    -1    -1     1
     1     1     1     1    -1    -1    -1    -1
     1    -1     1    -1    -1     1    -1     1
     1     1    -1    -1    -1    -1     1     1
     1    -1    -1     1    -1     1     1    -1

i want to keep the same values of the first and the last column and the first row and change the others like this

H =

     1     1     1     1     1     1     1     1
     1     a     a    -a     a    -a     a    -1
     1     a    -a    -a     a     a    -a    -1
     1    -a    -a     a     a    -a    -a     1
     1     a     a     a    -a    -a    -a    -1
     1    -a     a    -a    -a     a    -a     1
     1     a    -a    -a    -a    -a     a     1
     1    -a    -a     a    -a     a     a    -1

Answer 1

[Azzi Abdelmalek]

H=hadamard(8);
a=10
H(2:end,2:end-1)=a*sign(H(2:end,2:end-1))

%or simply

H(2:end,2:end-1)=a*H(2:end,2:end-1)

[Dija]

Thank you