Can I replace my Shimano RX 100 with a Campagnolo group?
As Pete H has commented, a partial swap will probably not work out.

On frames / bikes of this age, things were easier as compatibility was not quite so much of an issue, so some elements could probably work together OK - but if you are not sure / inexperienced, best is to swap everything.

Worth checking, though, that the threads for the bottom bracket on both frames are the same - some Concordes used to be Italian threads, your existing frame may be Enlish and they are not interchangeable.

To check which you have, measure the width of the shell, width-ways (i.e don't try and measure the diameter) excluding the cups that screw into it - 70 mm Italian, 68 mm English.