question

My immediate answer for you is "not out of the box". But you could still implement this feature as a calculation of multiple VC's.

Step 1, create the recharging VC, which (always) has a max of WAAAY beyond what your actual players' max values will ever be, for the life of your game. (This part is important).

So, basically, if 1 stamina represents 1 minute, set a maximum recharge at like... a year. Lets round up, and say 600,000 is the max stamina for every player, and every player STARTS with max, and go from there.

Have a second vc, which is the "actual" max, for this player, called maxStamina. This is not a regenerating currency.

SO, there's a hard coded constant:
MAX_REGEN = 600k
And Two variables:
stamina = (starts at 600k)
maxStamina = (1 hour would be 60, so let's assume that is your initial, and players can buy more)

Finally, calculations:
int spentStamina = MAX_REGEN - stamina;
int remainingStamina = maxStamina - spentStamina;
bool canPurchase = remainingStamina > 0;

So basically, "maxStamina" is how much you're allowed to spend, out of your ridiculously but invisibly large pool. Unfortunately you WILL have to do your purchase logic within a Cloud Script, because our default purchase logic will test that 600K is > 0, and that's the wrong calculation.

Recap:
What you're specifically asking for isn't supported, but the same effect can be delivered with multiple currencies, and a bit of Cloud Script calculations.