Matlab BOC (binary offset carrier)
First off- I know you are doing you're best (which is why I am answering) but your question is very hard to read.  Regardless of your English skills, it would be easier to read if you would break it up into paragraphs and throw in some pictures to help show what you're talking about.


  These 1023 chips (vector’s elements) should be repeated every 1 ms in order for the chipping frequency to be achieved (10Mchips/s).


1023 chips repeated every 1 ms means you have $\frac{1023}{.001 s} = $1 Mchips/s, not 10 Mchips/s.


  My first problem is that in the first place in order to demonstrate the spectrum of the codes,spectrul nulls should be represented at frequencies multiples of 1.023 Mhz.The only way that I could somehow think how to do this is to use massive vectors where are not really supported by my laptops memory (RAM).


You should not need a "massive" vector to demonstrate this.  Increasing the number of samples that you FFT just gets you better frequency resolution- it doesn't change the frequency range.  I think that you should be able to see the nulls just fine with several repetitions of the spreading code.


  I say somehow because the sampling rate should change (for example wherever I have one ‘1’ I should add some more and the same applies to zeros).


I have no idea why you say that the sampling rate should change, unless you're talking about going from the unspread rate to the spread rate.