Yes, you can cross band from a simplex frequency in one band to a repeater frequency in another band. However, you will have to wait until the repeater complete drops the signal before you can transmit again.
A better way if possible is if you can hear the repeater on your HT, set the cross band up as a "range extender". I.E. listen to the repeater on your HT and set up the TX frequency into the repeater.
Some HTs can do it, some won't. As bad as everyone hates the Baofengs, they will do that.