Yes there's no way to 'reshuffle' a card back into a specific (or even general) spot in Vassal, so that card can re-appear anywhere once back in the pack.
You can, but it would require some modifications. I see in the Editor that the Draw Pile is set to "Reshuffle: Always", meaning there is no set order to the cards in the deck. Every time you take something off, it's randomly chosen from what's in the deck--so the Reshuffle card could very well be the first thing drawn.
To guarantee the Reshuffle card goes into the middle, first you'd change the Draw Pile to "Reshuffle: Never". Then you'd create a non-visible deck that does
always reshuffle, and traits on all the cards to put them in this deck. With a series of Global Key Commands and a Multi-Action button for this window, you could end up with a single toolbar button that in one click does the following:
1. Put everything except
the Reshuffle card in the temporary/non-visible deck.
2. Pull half the cards out of this deck and put them in the Draw Pile (this randomizes the bottom half)
3. Put the Reshuffle card on the Draw Pile
4. Pull the remaining cards from the temporary/non-visible deck into the Draw Pile (this randomizes the top half)
It all gets processed so fast you don't actually see the cards moving to/from this non-visible deck...i.e., it's only there for deck construction purposes.
The possible drawback here is that you always know the Reshuffle card is in the 26th position. To build in a little uncertainty, you could use an additional non-visible deck and rejigger everything so that the Reshuffle card gets placed randomly in the middle 6/8/10/? cards of the deck. That would require a couple extra card traits and Global Key Commands.
Food for thought!