Curious

I was wondering if I can do this:

I was wondering if I can scan for a value while a program is running, then change it's value, then freeze the value so it won't change by itself after that. It's basically what Cheat Engine does. I was planning to get a string grabber of some sort, but I don't really know how to tackle it. After the scan finishes though, I can verify that it is the correct value and use the UDF I found, _MemoryWrite, to change the value, so I don't need any help with that.

I'm just curious if this is possible, as I thought of it randomly one night and thought of ways it could work. If this IS possible, can someone show me how someone would take  a grab at it?

Thank you,
~Divine