Random letter sequencing with a pattern

I'd like get random letters together to generate weird words with a specified pattern like cvvcv (consonants and vowels). No consonant variations like th- sh- ch- etc needed.

The problem is, when I attempt to do one, I have to specify the length of the word. However, I want the number of characters in the output to be the same in the pattern. I mean the length would be pre-defined by the character number of the pattern.

An example with a fiddle would be great and much appreciated.