Incorrect conversion from Excel to Word (ie MS Graph)?

I have a client who’s having a problem that’s absolutely stumped me. He works with extensive charts and data manipulation in Excel. He then copies this information into Word to produce his reports. We have a problem where he pastes his data into a pre-existing chart in Word, and the dates get messed up. What happens is he has the format for the column in MS Graph set for dates as Feb-01, etc. When he pastes the data in, Word or MS Graph changes it to 01-Feb. Now, even better, if he reselects the whole column and sets the format back to Feb-01, the tricky little thing ADDS a year, messing up the data. There’s no “Paste Special” for MS Graph, so I can’t tell what special formatting baggage is coming along with the data. Anyone have any ideas?