Dimmer switch electrics advise please!

[HollyBollyBooBoo]

I'd like to replace the current light switch in the conservatory with a dimmer switch. The current switch is a fused one (conservatory was an add on so presumably that is why). I assumed I'd have to replace the switch with a fused dimmer but they don't seem to exist!

Do I have to replace like for like or what other kind of dimmer could I use?

Thanks!

What I guess has been done is that when they added the conservatory, the lights were fed from the mains ring circuit and not the lighting circuit which would require a switch fused spur . the fuse would have to stay, how about adding your dimmer in a second box alongside ?