Play a Warlock
You'll be going after a blaster archetype from the optimization thread here. As a point of order, there is no difference between high accuracy and low damage versus low accuracy and high damage within the bounds you are talking about. Inasmuch as accuracy is a multiplier applied to damage, the trade of accuracy for damage is purely cosmetic.
To restate your requirements: you are looking for an artillery focused warlock instead of skirmisher, for low to mid heroic.
This is quite doable, but there are many traps.
I'd personally go with sorcerer-king pact, as it provides a nice flexibility to range (in case you find yourself in melee) and the hugely impressive Mindbight Scorn. With hand of blight and mindbight scorn, your attacks will be doing necrotic and psychic damage, a combination which is very rarely (if ever) resisted given that you take the lowest resist out of all keywords on the power.
Drow is a good choice. While for flavour you'd be serving a sorcerer-queen rather than king, the +2 dex qualifies you for dual-impelment spellcaster without too much trouble.
Here are your recommended feat choices:
1: Mindbight Scorn (+1d6 pyschic damage against cursed enemies)
2: Killing Curse (+2 average damage (turns your curse d6s into d8s)
4: Rod Expertise (+1 accuracy with rods, as well as some defensive buffs) (I'd prefer staff, but multiclassing to get staff proficiency isn't indicated at low levels)
6: Dual Implement Spellcaster (At this level, you'll have a +2 and a +1 implement, giving you +1 to +2 to damage)
8: Superior Implement Training (one of the rods based in an element you use often)
10: Bloodied Boon
Stats are Cha/Int, with a 13 dex after racials.
Recommended powers are:
1e: Cursebite (If you can start out with a rod of corruption and you're above level 1. Otherwise retrain this when you get a rod of corruption) or Cruel Bounty
1d: Crown of Stars
2: Spider Scuttle
3e: Shared Agony (use it early)
5: Hunger of Hadar (party has to have some pushes. but it's very fun.)
6: Fate's Frayed Thread (since you should have cursebite by now)
beyond this, take what your party needs.
This is an arcane striker that does the whole warlock feel (by definition) but at range, the "inspiration" for the hexblade. I suspect you'll be quite happy with a well built warlock.
The strongest ranged striker after mid-heroic is the Ranger
Or equivalent characters using twin-strike via half-elf. Another strong striker is a hellish rebuke infernal warlock (especially after mid-heroic). Both warlocks and rangers have excellent mobility. A fantastic striker, if you're looking for a bit more interesting tactical situation is a crossbow thief or rogue. The process of gaining combat advantage makes the turns slightly more interesting than ol' "twang-twang" (which quickly became our rangers nickname since that's what she did every. bloody. attack.)
Interpreting the question of "How can we make a drow hexblade" (or equivalent) into an interesting and strong ranged striker. Drow are known for their dual hand-crossbow feat, leading us naturally into drow thief (since I refuse to stat most rangers because twin-strike is boring.) As a hand-crossbow, sneaky (with darkvision) character, everything slots naturally into a highly effective ranged striker with good AC/reflex due to dex and high mobility due to thief utilities. MC seeker (and flavour it a bit warlocky so your bolts are surrounded with eldritch flame) for primal eye in paragon. Plenty of damage there, as well as a mildly interesting striker.
Take a look at the charOp boards for some tips on how to optimize any class.