Shimano 9 to shift 7 gears

Hi there.

I've probably got things confused but what the heck I'll ask here to
be sure. VBG LOL

I know you can use a Campy 9 speed brifter and a modern Shimano rear
mech and a 7/8 speed chain to shift a Shimano 7 speed cluster.

Is there any way you can use a 9 speed Shimano bar-end shifter and a
Campy rear mech to shift a Shimano seven speed cluster? Without using
a shift-mate that is.

Thanks and cheers from Peter