Referring to the status codes the game can have (for gen3 in particular): https://github.com/pret/pokeemerald/blob/c9c754be061c6400a0eaf60a01ccd0dcafb01b91/include/constants/battle.h#L97-L108
#define STATUS1_NONE 0
#define STATUS1_SLEEP (1 << 0 | 1 << 1 | 1 << 2) // First 3 bits (Number of turns to sleep)
#define STATUS1_SLEEP_TURN(num) ((num) << 0) // Just for readability (or if rearranging statuses)
#define STATUS1_POISON (1 << 3)
#define STATUS1_BURN (1 << 4)
#define STATUS1_FREEZE (1 << 5)
#define STATUS1_PARALYSIS (1 << 6)
#define STATUS1_TOXIC_POISON (1 << 7)
#define STATUS1_TOXIC_COUNTER (1 << 8 | 1 << 9 | 1 << 10 | 1 << 11)
#define STATUS1_TOXIC_TURN(num) ((num) << 8)
Assuming you want to set a Burn status, the value would be (1 << 4), aka 16.
So, in the batch editor, you select the Party button and run the following instructions to edit your party slot (zero indexed, so your first party member is 'slot 0'):
=Slot=0
.Status_Condition=16