I have tried a battle cleric - here's the best way to do it.
1. Race - Dwarves seem to make the best battle clerics due to their stats. Halflings seem to be a close second, followed by Humans. I would not suggest high elves, gnomes, or (ugh) erudites.
2. Start from the begining - keep your weapon skills up and your offense and defense skills up as best you can. All of your basic combat stats should be at least 75 (str, dex, agi, sta).
3. Wear Plate - this may seem obvious, but your best bet is plate. I would suggest for a starter Gothic or a combination of Gothic and sandblasted - you can get other stuff if you can find it, but the gothic seems pretty common enough.
4. Fight Undead - when possible, in a group or soloing, your best bet is to fight undead. Remember, "battle" doesn't mean that you have to tank from start to finish. You are no less "battling" the mob if you root it, nuke it a bit, then run up and bash it to goo. The reason to go for undead is the fact that your abilities are best for those types of mobs. Rangers don't fight undead, they fight animals, since thats what their abilities are best suited for.
5. Go anon/role - Ok, I don't actually condone this - and be careful if you do, however most clerics could pass off as a paladin if anon. More experienced players should be able to tell by your lack of bow for pulling, or that you have less hp, or that your not bashing, but newer players may not. Being temped and saying your not temped could further the charade.
6. Try to group more than one cleric - to me this is the best way. If you have two clerics then there is no reason one can't get into the fray - saving mana for back up heals.
7. Finally - know your limits - your still a cleric - if you've ever played D2 and tried a battle-socorceress, you'll know that its not an easy combination - learn to use your abilities to augment your combat, you want synergy.
actually I guess finally is have fun. you may feel your best bet to do this is the FV server, they can't hate your for roleplaying there