I am going to run a free dynamic redirect website, but there are some difficulty that I'm facing. There are some operation that I would like to achive any of the follwing:

1. memAcc.myDomain.com redir to memIP
2. memAcc.myDomain.com redir to memURL.com
3. memAcc.myDomain.com/memPage.html redir to memURL.com/memPage.html

In fact, I have searched some forums reguarding these issues, I found:

For problem 1 & 2, I can use DNS record to achive:
memAcc IN CNAME memIP
memAcc IN CNAME memURL
(let me know if I am wrong)

For problem 3, apache rewriteRule in .htaccess, this I don't know how to do it. If anyone knows how to do it, please let me know.

Is there any different if I use wildcard dns and php+mysql to do it?