Squirrel 3.x (classic) and 4.x
open a command prompt by clicking start > run > type 'cmd' in the 'open' box, and press enter (NT and XP, for 95 type 'command').
type sdt and press enter, which should take you to c:\squirrel\data\today
type 'copy hcm*.dat c:\' without quotes and press enter. if done correctly, you will see at least '1 file copied' above the line with your flashing cursor.
type cd\ and press enter. this should take you back to c:\
now type 'dir hcm*' without quotes and press enter, which should list at least one file called hcm_0.dat, but could include more starting with hcm_1.dat, hcm_2.dat, etc.
type 'notepad hcm_x.dat' without quotes, where x is the sequenced number you wish to open. always start with hcm_0.dat and work your way up from there. if done correctly, this should open the file in a notepad window, which will look like a bunch of gibberish, as it's a log of the communication between the terminal/host pc/credit card network.
in NT click 'search', in XP click 'edit', then 'find'. in the search for box, key in the last 4 or 5 digits of the CC you are looking to retrieve (depending on how many the version you are on is masking).
if the file contains the CC# in question, it should show up at the bottom of the window highlighted in blue, the preceding numbers should be the 1st 3/4 of the card number you are looking for. If the number doesn't look like a full CC, click 'find next' until you either find the number further on, or it reaches the end without finding the number at all, in which case you would close the window, and move on to hcm_1.dat, etc.
once you have it written down, simply close off notepad, and the command prompt, and you're done.. go re-enter it from a terminal.
SquirrelOne
the steps are almost identical, just the location the files live in is different.
open a command prompt, and type 'cd squirrel', press enter, then 'cd host', press enter, then 'cd host1' and press enter. this should put you in c:\squirrel\host\host1, from there, follow the steps above to copy the hcm files to c:\, and open in notepad as outlined above as well.
the reason you should copy them out of the folders they live in before opening them is that the system is constantly writing to those files while it is up and running. If you were to simply open it up, you could potentially corrupt the file.
Hopefully this helps, it's the steps the solution center will walk you through if you call, so if you feel uncomfortable with this just call it in and they will walk you through it.