Package/script for random DNA generation with a pattern!

Question

[Parham]

Hi,

I want to design oligos to test some methylation digestion assay on them. I am looking for a software/package that helps me to have control over these parameters:

1. Length of the oligo.
2. Include or not include a specific pattern (eg. CCG, CCNG, etc)
3. Specify number of pattern instances (to have two, five, etc times of that pattern in the sequence.)

If you have any recommendations I will be happy to know.

[Dunois]

Maybe it's time to write a package in R to plug this niche? If you're planning on doing that, I'd like to help.