How to perform regression on panel-data with timelag in SPSS?

#1
For my thesis, I have gathered search volume data ("svi") from Google and message data from Twitter ("tweets" is the number of daily tweets) for serveral companies ("comp"). The variable "tradevol" is the trading volume in the stock of a company, as taken from Yahoo! Finance. "svi" and "tweets" are my independent variables, "tradevol" is dependent.

For argument's sake, say I have collected data over 3 days for each of 3 companies (in reality, I have data for 100 companies gathered during 200 days), as follows:
Code:
    comp  date   svi  tweets  tradevol
    -------------------------------------
    1     02-12  1.07  223    2,209,425
    1     02-13  1.03  200    2,021,502
    1     02-14  1.10  196    2,124,555
    2     02-12  0.55  110    1,942,211
    2     02-13  0.45  211    1,532,453
    2     02-14  0.41  104    1,432,655
    3     02-12  1.05  303    1,765,273
    3     02-13  1.08  250    1,932,672
    3     02-14  1.09  277    1,597,892
A dataset like this with measurements over time goes beyond what has been tough during my studies. So I need to understand how to analyze this. Therefore, I have some questions analyzing this dataset in SPSS / PASW.

  1. How can I, from this dataset, measure the correlation between svi and tradevol for each company? I would then somehow have to tell SPSS to split the datafile on comp, calculating the correlation for each unique comp
  2. My thesis-coach calls this dataset a "panel dataset". However, searching for "paneldata analysis SPSS" I don't find much usefull information. If I want to perform a regression, measuring the effect of `svi` and `tweets` on `tradevol`, how is this then called? A multilevel regression?
  3. Regarding regression, my coach wants me to account for a timelag. For instance, today's `svi` and `tweets` may not have an effect on today's `tradevol` but perhaps there is an effect (or: a bigger effect) on today's `svi` and `tweets` and tomorrows `tradevol`. In this case, I would have to perform the regression for lag t-2, t-1, t, t+1 and t+2. Is this operation possible to perform with SPSS (18) and if so, please send me something to go by.

Any help is greatly appreciated :)