Well lets look at them and see if it is possible.
Beretta M92 mag. ProMag BersaHC9mmPro
This ProMag is not the exact same thing as a OEM Bersa HC9P mag.
And as I can not find any actual pictures of the Bersa HC9mmPro magazines. Even on the Eagle Imports web sight they don't have pictures.
I have a 15 inch display set to 1280x800 res.
My Bersa HC9mmPro magazines are almost the exact same size as this picture. Beretta M92 mag
They are not exactly the same but they are very very close. With some filing at the mag disconnect hole you might be able to make them work.
I bought 4 of the Bersa Factory mags for mine. I wanted to be sure they would work.
Have not found any after market mags for this pistol as of yet that are drop in replacements and this ProMag is not a drop in so far as I can tell.
And it looks like MecGar does not make mags for Bersa.
Not much but I hope it helps some how.