collating data, minimum interval

[CLReynolds]

Hi everyone,
I'm hoping I am not repeating a previous question (I did try to check). I am trying to collate data from multiple sheets based on the minimum interval with a key identifying field. I think this is best demonstrated with the example below:

sheet 1 ID	attribute 1	attribute 1 from	attribute 1 to
1	A	0	10
2	B	0	10			ID	From	To	attribute 1	attribute 2
		1	0	5	A	C
		1	5	10	A	D
sheet 2 ID	attribute 2	attribute 2 from	attribute 2 to			2	0	7	B	null
1	C	0	5			2	7	10	B	C
1	D	5	10
2	C	7	10

<tbody>
[TD="colspan: 2"] collated with [/TD]

[TD="colspan: 2"] produces > [/TD]

</tbody>

What is my best way of going about doing this?
Much appreciated,
Catherine