I work on windows mobile full time and have never really come across a good Windows Mobile scripting implementation unfortunately. For some reason MS has never seen the need for it. For example, even though you can actually get a command console on WM, it does not support running batch files, even though all the commands are still there and it would be relatively easy. There is definitely not a VBScript engine I've ever heard of nor JScript. There is PythonCE but the WM specific support is minimal and you don't get access to a lot of WM only things.
Also, I've done a lot of work with a company called SOTI which has a product called MobiControl that does incorporate a basic scripting engine. Though most of the commands are specific to their system and actually have to be run from a desktop-side management console.
Given all of the times I have tried to find a good scripting engine for WM myself you would think I would've just written one ;)
So, sorry, but the basic answer is no, there is not a scripting engine available for VB in the context that you specified.