There is item Jump to virtual address on Tools menu. If you click to the item, you will see a dialog window. Just input the address in text field and press Ok. Virtual address is a pointer to code in program memory. VB Decompiler is using only virtual addresses, therefore any address from decompiled code is virtual address and can be used for Jump to virtual address function.
You can use Ctrl + G for more faster jump to virtual address. Just select needed address in decompiled code (it can be function call or jumping inside selected code) and press Ctrl + G. Jump will be done and the code will be decompiled.
To return back to previous function after jump, you have to use buttons with arrows on tool bar. This buttons can be using to turn back or jump forward on already seen code.