Another question about mask to deal with space

[gale6k]

I want to separate a big task to small ones and running on several machines.
For example, I want to exhaust eight ?a password space, I separate it to
?a?a?a?a?a?a?a0
?a?a?a?a?a?a?a1
?a?a?a?a?a?a?a2
...
, then I can run separated small tasks on several machines.

But if it occurs '?a?a?a?a?a?a?a ' or maybe some other special characters, I do not know how to deal with it.