This study investigates a control strategy for spatially selective torque density application to microrobots using rotating magnetic fields (RMFs) combined with magnetostatic selection fields. The approach aims to enhance the targeting of microrobots, particularly magnetotactic bacteria (MTB), to deep-seated tumors while suppressing off-target actuation in healthy tissues. Numerical modeling and in vitro experiments demonstrate the suppression of off-target torque and the ability to focalize torque application, respectively. A mouse-scale torque-focusing apparatus is designed and constructed, capable of maneuvering the focal point within the tumor. In vivo studies in a mouse tumor model show increased accumulation of intravenously injected MTB within tumors receiving focused actuation compared to non-actuated or globally actuated groups. This control scheme combines the advantages of torque-based actuation with spatial targeting, offering a promising approach for improved therapeutic delivery and immune modulation in cancer therapy.This study investigates a control strategy for spatially selective torque density application to microrobots using rotating magnetic fields (RMFs) combined with magnetostatic selection fields. The approach aims to enhance the targeting of microrobots, particularly magnetotactic bacteria (MTB), to deep-seated tumors while suppressing off-target actuation in healthy tissues. Numerical modeling and in vitro experiments demonstrate the suppression of off-target torque and the ability to focalize torque application, respectively. A mouse-scale torque-focusing apparatus is designed and constructed, capable of maneuvering the focal point within the tumor. In vivo studies in a mouse tumor model show increased accumulation of intravenously injected MTB within tumors receiving focused actuation compared to non-actuated or globally actuated groups. This control scheme combines the advantages of torque-based actuation with spatial targeting, offering a promising approach for improved therapeutic delivery and immune modulation in cancer therapy.