A while back I published several blog posts about reverse engineer a number of wireless sensors:
http://rayshobby.net/reverse-engineer-wireless-temperature-humidity-rain-sensors-part-1/
It was a challenge but a really fun experience, and with it you can pretty much reverse engineer any fixed code (i.e. not rolling code like garage door remotes).
When I say solder wires, it’s soldering onto the remote, not the window blinds. If that still sounds messy, perhaps you can get a spare remote just to be used with Arduino. This way, you have one remote for manual control, and one soldered to Arduino for programmable control.