Confusion for Stage 3

I misread sthe stage three puzzle (although the pic should have given me more hints)..

I though it was lower surround by 3 capital, including the upper and lower lines, like this:

oooooooXoooooo
ooooooXoXooooo
oooooooooooooo

There are four different solutions to this and I was trying to use RE to do it, I had not really used Regex before and though i was just dense..

I found the actual puzzle a lot easier than my made up one. And I have learn regex a little, which is good.

But my question is can regex be used to solve my more complicated puzzle with one regex???

I'm curious Now;)

Pablo