How are you 'merging' the figures from Excel to Word?
You can easily round off your figures within Excel and then send the data to Word:
If the figure you want rounding off was in cell A1, you could use the formula
This would give you $412.00
Or, you could simply refer to the cell you're copying but change the format of the cell, so in cell B1 you'd enter:
Then select B1 and go to Format > Cells > Number tab. Set the Category to Currency and Decimal Places to 0.
This would give $412