Don't know if you can load characters based off of these text files in any way, but here is Mirage built using it.
[sblock=notepad version]====== Created Using Wizards of the Coast D&DI Character Builder ======
Mirage, level 6
Tiefling, Wizard
Build: Control Wizard
Arcane Implement Mastery: Orb of Imposition
FINAL ABILITY SCORES
Str 8, Con 14, Dex 10, Int 20, Wis 12, Cha 16.
Starting Ability Scores
Str 8, Con 14, Dex 10, Int 17, Wis 12, Cha 13.
AC: 19 Fort: 16 Reflex: 19 Will: 19
HP: 49 Surges: 8 Surge Value: 12
TRAINED SKILLS
Arcana, Insight, History, Diplomacy, Bluff, Stealth.
FEATS
1: Ritual Caster
1: Improved Initiative
2: Skill Training (Bluff)
4: Skill Training (Stealth)
6: Toughness
POWERS
1, At-Will: Illusory Ambush
1, At-Will: Scorching Burst
1, Encounter: Grasping Shadows
1, Daily: Phantom Chasm
Spellbook: Sleep
2, Utility: Phantasmal Terrain
Spellbook: Feather Fall
3, Encounter: Maze of Mirrors
5, Daily: Phantasmal Assailant
Spellbook: Fireball
6, Utility: Invisibility
Spellbook: Levitate
ITEMS
Spellbook, Bloodthread Cloth Armor (Basic Clothing) +1, Adventurer's Kit, Dagger, Orb of Impenetrable Escape +2, Cloak of Distortion +1, Phantom Soldier (heroic tier), Potion of Healing (heroic tier), Potion of Mimicry (heroic tier), Comprehend Language, Secret Page, Silence, Eye of Alarm, Detect Secret Doors, Knock, Hallucinatory Item, Sending
====== Created Using Wizards of the Coast D&DI Character Builder ======[/sblock]
EDIT: Actually the .dnd4e files are just xml text files. Save these in your Saved Character files and you should be able to pull him up. Heck its even an allowed file type here, other people must've had this idea already.