If you could list a step-by-step process on how to do something like this, that would be great!
In theory it's possible to use a Sprint CDMA phone on a Verizon network as they both have basic interoperability with each other's networks.
The problem is that the carriers themselves do everything possible to prevent movement of handsets across each network. I assume this helps prevent churn, or customer loss to other networks.
From my perspective, I've noticed that when we mod and root phones, each custom ROM is specifically designed for a particular network. Which means that even if you were able to convince a customer service rep to activate a competitor's phone on their network, the phone wouldn't work unless you had flashed a ROM that was specifically designed for that network. The Conquer, fortunately, is on both networks, so it's entirely possible that customers have migrated over from Sprint to Verizon.
The only place I can think of where there's experts who know something about this is in XDA's CM7 Conquer on Verizon thread. If you ask these guys, they might know.
It's not possible unless both the carriers are on same frequency band and since your phone is made to work for only Sprint's frequency band,hence it wouldn't work in Verizon's network.