LCALL anywhere

puts a 16-bit value in the stack. This value is the address of the instruction that follows the LCALL, that is, where the subroutine must return to.
You can write a simple soubroutine,

anywhere:
<your code>

to determine the PC value before LCALL was executed (substract 3).

This trick is frequently used when setting breakpoints for debugging.

Regards,

Alfredo del Rio.