Basically it will just thin the oil out. Change the oil and filter and you will be ok.
If you have any further questions, please feel free to reply.
Will it do any damge to the engine if it was ran
No, it really wont. The only way it would is if it was driven for ALOT of miles on trans fluid only. Actually it works real for an engine cleaner. We used to put some in the oil on purpose for engines that had alot of sludge build-up, run it for awhile, then drain it out. So it probably actually did your engine some good :-)