If we must, I can put together something. I'm not certain that the rookie cap is set only on this year's numbers but that's the only way I expect I could come up with numbers.
First round
Expect a $40 mil over six years or so contract. $8 mil bonus, something above the minimum for base salary - let's go with $500k for simplicity. $1.833 million, so let's round up to $2 mil to be safe.
Second round
High second rounders often get deals for four years, I'd estimate around $3 -3.5 million. Let's say $1.5 mil bonus and the first year minimum. $595,000 salary cap cost for 2002.
third round
Often a three to four year deal. For now let's go with 4, $1.8 mil. Bonus - $600k. $370k cap hit.
fourth - sixth
mean average of $150,000 signing bonus, let's say out of thin air.
Add in the base of roughly $220k minimum per player and you're talking $1.1 mil. Unless you're talking three or even two year deals, which can happen by the 6th. I believe we've usually worked toward three year deals here on down but I'm feeling lazy.
Seventh
$60,000 bonus plus minimim, two year contract. $250,000
On the other hand it's unlikely that the fifth through seventh will make the slightest dent in the top 51 salaries, which is what counts until the regular season. Therefore a team's rookie cap and salary cap overlap in most instances.
Total? $4.315 million. But yet again you're not going to find more than three players out of the group that are going to count again st the top 51, and pretty much you won't know what to do with this information. Therefore I was reluctant to do this. But here you go.