If you keep your HT programmed to that frequency (with no tone), when using the repeater, if you can hear the other party transmitting through the repeater on both radios, then you can probably successfully transmit simplex to that GMRS repeater user, as well!
Remember that 50 watts simplex is only allowed by the FCC Rules for 462: 550, 575, 600, 625, 650, 675, 700 and 725!