An autohotkey script that sends the correct key sequence should work, though: send Tab, Ctrl+T (for new tab), Tab again, then Ctrl+Right arrow.-tranglos
thanks to your input, i've managed a rudimentary script with the "PostMessage" commands that seem to work on my PC, so far..
just in case, if anyone needs it. i'll post it here.
#IfWinActive ahk_class TTOTAL_CMD
cm_OpenNewTab := 3001
cm_OpenDirInNewTabOther := 3004
;ctrl + shift + left arrow
^+Left::
Send, {Tab}
PostMessage 1075, %cm_OpenNewTab%, 0
Send, {Tab}
PostMessage 1075, 3004, , , ahk_class TTOTAL_CMD
Return
;ctrl + shift + right arrow
^+Right::
Send, {Tab}
PostMessage 1075, %cm_OpenNewTab%, 0
Send, {Tab}
PostMessage 1075, 3004, , , ahk_class TTOTAL_CMD
Return
#IfWinActive