If you wire full path to file path, you should not get dialog.
Try this example: http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=EECA254B0EC70B87E0340003BA7CCD71&p_node=%20DZ52027&p_submitted=N&p_rank=&p_answer=&p_source=External
I think it is what you need.
Cheers
Alipio
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"Qod natura non dat, Salmantica non praestat"
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