I would write this in C# using the .NET framework. I have written a similar application using vbscript as a command line tool for an enterprise level network admin crew. To complete I would need to know if you wish to replicate the functions of ADUC or just a subset, I would need to know your AD schema, and the OS version you will run this from.
I look forward to working with you on this project.
Dave Buhl, Founder
Buhl Software