Command Prompt

Hi, noob here, just requesting a bit of info then I'll be out.
I have a file and I want to read a specific number of bytes then delete a similar succeeding amount.
It would then ignore the bytes after that then continue to delete as mentioned.
Sorry if I was unclear. For example, keep 1 byte, delete the next, keep 1, delete next, etc etc.
I'm guessing you could do this through Windows Command Prompt, but how? Many thanks in advance.

Also if it isn't too much trouble, how could I create a file like  this from two sources?
It would read a portion from 1 file then add a portion from another. Supposedly splicing but hey what do I know.

>>5

Many thanks. I get what you've done, but pulling it off is pretty much beyond me already.
It pains me seeing the skip, the write, etc... but getting it into an actual command or something I can run still has me searching.
Is the Command Prompt even an option for this? At the least it looks like I'll have to script it or something.