You haven't told use which way you want to rotate! Or do you just want to shift?

Your example doesn't work as you can't use an indirect operation on a bit. You can do the following on bits:

set setb
reset clr
complement cpl
move to/from carry mov C,bit or mov bit,C
jump on condition jbc,jb

( I think i've covered them all!)
so the mov @r0 isn't going to work on bits (unless you want 8 at a time)

so you have two choices:

inline code using bits:

mov C,bit3
push acc ;save bit to rotate around
mov C,bit2
mov bit3,C
mov C,bit1
mov bit2,C
mov bit0,C
mov bit1,C
pop acc ;recover the last bit
mov bit0,C

this is a bit labourious but in some instances may be a good solution.

or:

bit0_7 equ 20h
mov a,bit0_7
rr a
mov bit0_7,a

I suggest you read the 'bible' on shifting and rotating for more background. Also read as many app notes that have code examples to get a feel for how things are normally done. There's also heaps on examples kicking around the web for you to learn from.