You can enter a Unicode Character in emacs with the following sequence:
C-x 8 <enter> <character code> <enter>
If Unicode is supported on your installation you should see an ‘Insert character’ message after pressing enter for the first time. If it is not supported then you will get a message along the lines of ‘C-x 8 not defined’.
To get a small e with an accute accent you would use the character code ‘e9’, so the full sequence would be
C-x 8 <enter> e9 <enter>
You can find lists of character codes at the following sites: