DataTable multi select - overriding with CNTRL or SHIFT

I need to be able to configure TableTools to do multi selects with more standard GUI defaults ("Hold CNTRL to select Multiple"). The most important of these two is the CNTRL method. Essentially it would function like this: once "sRowSelect" is set at "single", holding the CNTRL button would move you into "mutli" select mode. Release the CNTRL button would put you back into "single" select mode. Any one found a way to do this or at least perhaps a button to toggle between Single and Multi select?

Also, as an additional bonus, it would be great to have the other GUI default ("Hold SHIFT to Select a range"). But that one is not pressing for my needs right now.