Error: Compiling vb.net with vbc

Hi,

I've an application which I've built in vb.net and it uses vb6 mid len functions, by referencing the visualbasic namespace. Now I want to compile the application into winexe so that I can schedule it to run using windows task scheduler.
But the problem is, when i tried to compile using vbc from the command prompt, it gives me error which is attached...

len needs to be declared, txttest needs to be declared and so on...

Any suggestion is really valued..

Thanks