you can't.

Will the option of emulating 4.77 MHz speed be a future version of DOSBOX?

unlikely

Depending on how the game does its timing you don't need exact cycles
matching, which is impossible anyways so just play with the cycles until
it seems right.

May I ask why?

Other emulators emulate exact speed. The Amiga emulator, WINUAE, emulates at exact speeds and so do other emulators. Why can't this be done for DOSBOX?

It could, but DOSBox currently doesn't track cycles. http://www.mess.org/ does, and it emulates several x86 PCs. Old systems would take x cycles to execute a particular opcode, accessing a bus, io, etc would take so many cycles to access, and so on. winuae, mess, etc. for every opcode they execute and access they do they keep a tally of the cycles it would have cost on the original system.

How is MESS compared to DOSBOX? Does it emulate DOS as well as DOSBOX does?

DOSBox is better, but MESS handles a subset OK. If you need more cycle accurate emulation, though MESS still isn't perfect, and the program is old, aka CGA, it's something to check. There's others to try too, like http://www.hampa.ch/pce/index.html.

I wouldn't bother with MESS, the emulation may be more faithful to the original, but its use is far more complicated.

I've played very old stuff in DOSBox, and usually works fine between 400 and 700 cycles, depending on the game.