Hello,
The "reserve army" crossed the Alps from the 15th of May 1800 until the 25th of May.
Here are the Hussars regiments :
11th hussars (4 squadrons, 518 men)
12th hussars (4 squadrons, 596 men)
1st hussars (1 squadron, 120 men)
+
1st hussars "cisalpin"( 3 squadrons, 300 men)
hussars "volontaires" (120 men)
Hope it will help you.
Best regards.