You can.
Get an USB IR dongle from a IR PS3 remote (search amazon for it) and either control the PS3 directly with your Beo5 or, plug an IR transmitter cable in the back of your BV7 and glue that remote eye to the USB dongle (B&O dealer has those cables)
Check the PUC list, if there is the PS3 remote installed, otherwise update the software of your BV7.
Once you've added the puc command, you can control the PS3 with your Beo4/5.
The only thing that isn't working, is PS3 power on/off.
Regards
Stephan