You can't translate one to the other like you do inches to cm because the two formulas use different variables. But if you take his stats for his senior season and plug them into the NFL formula you get a rating of 100.6. BTW his college passer rating was 148.3 not 105.3 which would actually be awful for college. 148.3 on the other hand if pretty respectable. Nevertheless I don't think it means much though since he wasn't playing against NFL talent.
And for those who are wondering what the differences in the two formulas are check out this article:
http://en.wikipedia.org/wiki/Passer_rating
And just for the record I'm not some geek who just spent hours calculating those ratings. I cheated and plugged his stats into this website.
http://www.primecomputing.com/