Other than taking the Adamant Arrow Style feat, how can I use powers in place of a ranged basic attack?

Question

I am playing Ranger in D&D 4e and I built myself around Flying Steel and other attacks that let you make a ranged basic attack when (trigger).

I want to know if there is a way that I could use an at-will attack power in place of a ranged basic attack.

I have already taken Primal Sharpshooter multi-class feat for Seeker for use of biting swarm. Primal Sharpshooter: Use of inevitable shot once per day. Use of inevitable shot is not regained when spending an action point. Use of one 1st-level seeker at-will attack power once per encounter.[PH3:193]

Is there a feat or a paragon path I could take that would allow this?

Answer 1

A singular feat? No. You would have to take several feats, but then Paragon Multiclassing would gain you one seeker at will for yourself in place of a Ranger at-will

From the PHB pg 209 (emphasis mine)

Paragon Multiclassing

If you have the Novice Power, Acolyte Power, and Adept Power feats for a class, you can choose to continue to gain powers from that class rather than take a paragon path. If you choose this option, you gain several benefits.
At 11th level, you can choose to replace one of your at-will powers with an at-will power from your second class.

This would require 3 feats, which allow you to switch out ranger powers (1 each of encounter, utility and daily) and you would be giving up any other type of paragon path.

It's probably too late, but Half-Elf's Dilletante combined with the paragon feat Versatile Master from PHB2 would also accomplish the task, with any RBA at-will.

TL/DR: Paragon Multiclass or be a half elf.