Can a participant who has a contributory ira with after tax dollars and pre-tax dollars in it roll or directly transfer the entire amount into a qualified 401(k) plan?

I'm confused on the new reg's. It appears there is no problem with the pre-tax IRA, or a rollover IRA (consisting of after tax employee contributions within a qualified plan ) but I not clear on just a plan ol IRA that consist of pre-tax and after tax money.

After help would be appreciated.

Only pre-tax amounts can be rolled from an IRA to a qualified plan. After tax ( non-taxable) amounts and amounts representing required minimum distributions and excess contributions cannot be rolled to a qualified plan