I haven't tested this personally, but I think this could work.
Guitar > Vox Input Jack > Vox Effects send > Pedal 1 (Mono In/Stereo Out) > Pedal 2 (Stereo In/Out) > Axe Fx Input 1 (Left+Right)
Output 2 Left > Vox effects return (Output 2 L+R if you have stereo effects loop on the Vox)
Output 1 L+R > PA
On the grid, create a row of shunts all the way across.
At the beginning of the grid, branch off the main line with a new shunt. On that branched off shunt, put an FX Loop block to send your signal immediately back out to Output 2 Left + Right. If your Vox is fancy and has stereo effects loop, connect to that from Axe FX Output 2 Left+Right. If your Vox is NOT stereo effects, which is more likely, go to I/O menu and change Output 2 Mode to "Mono" and just use the Output 2 Left.
Next on the grid, on the main line of shunts, put an Amp Block and choose "Tube Pre" to apply some power amp tonal coloring. Leave the Bass/Middle/Treble knobs at noon. Adjust Drive and Master Volume to taste. Change Power Amp tubes to "EL84" to simulate the power amp section of your Vox**. Put in a cab block and use your desired IR. This will go to Output 1 Left and Right. You send this to the PA and it'll be in stereo for the audience.
** If you're feeling really particular, temporarily put an Amp2 block anywhere and check out the settings for one of the Vox AC30 models. Make note of the settings in the Power Amp tab and apply them to the Amp1 block with the Tube Pre model. Delete Amp2 block when done.