Check you broadcast frequencies again. We run multiple wireless at church all the time, as do community theaters and pros all over the world. How are you connecting them to the Compact? If you are using a mixer, simply put each mic on a separate channel.

I just bought a Behringer Xenyx 1202FX mixer at GC for $89 - what a buy for 4 XLRs, 12 total input channels and 100 24-bit EFX. Sale is for $99, but I got the salesman to give me a 10% "coupon."