Is it possible to paste CSV formatted data into Excel 2007?

You need to insert your data into one column. Select this column, go to the Data menu and press the Text to Columns button.

For visual assistance, see this screenshot.

default menu:

data menu:

Mark (a.k.a. select) the same number of columns expected to be imported from csv and import (paste). For example:

Name;surname
xxx;yyy

Mark columns A and B, then paste.

If you can produce tab-delimited data, you can paste directly into Excel.

If you cannot get them to send you tab-delimited (as opposed to comma-separated) e-mail, this still involves one intermediate step (e.g. paste into notepad, replace all commas with tabs, copy again) but at least you don't have to save into and import a temporary csv file.