Is there any way to do this?

[TNoob]

I want to make somebody an administrator, but I don't want him to be able to delete posts/threads or remove me from being the lead administrator myself.

[Uhura!]

Then make him a Moderator. 



OR - create a usergroup titled "Administrator" but only grant the group  moderator permissions.

[Paul_Pauline]

Think long and hard before giving someone access to your Admin Control Panel.

Then don't do it !!!

[Matthew K.]

Giving access to your Admin panel is not necessarily a bad thing, but if you can't trust them to not delete posts, they shouldn't be under an Admin membergroup.