Two lights, two switches... one problem!
The following should work based on your comments:







simulate this circuit &ndash; Schematic created using CircuitLab

This requires that SW1 is a SPDT switch, which are commonly available for commercial light switches. In the UK these are called "1 gang 2 way".

When SW1 is turned on, it will turn on L1 only.

When the PIR is turned on, it will turn on either both L1 and L2 (if SW1 is off), or just L2 (if SW1 is on).

SW1   PIR  |  Lamp1   Lamp2
-----------+----------------
Off   Off  |   Off    Off
On    Off  |   On     Off
Off   On   |   On     On
On    On   |   On     On


This means that both L1 and L2 will be illuminated by the PIR regardless of SW1. And only L1 will be controlled by SW1.

As pointed out in the comments, this circuit should only be used as shown above, with a common live. If you house has more than one live phase, make sure both lamps are on the same phase and fuse/breaker.