How do i connect preamp rca to amp xlr

Gentlemen,

i have a cxn v2. Streamer. It has line output RCA and balanced output XLR

i have a pre-amp that only uses RCA

i have an amp only with only XLR

How do I connect them?  Ditch the pre-amp for one with XLR?

Can a shop somewhere add a balance XLR input and a set of the same for the outputs or does that sound too difficult?