As Rich says, push and pop may well be the cleanest way to get more variables now:
http://www.picaxe.com/BASIC-Commands/Advanced-PICAXE-Configuration/push/
http://www.picaxe.com/BASIC-Commands/Advanced-PICAXE-Configuration/pop/
Also see pushram and popram in the online "BASIC-Commands" page
You can use one of your named registers as a scratch register, and then use upper ram (above address 27 for the M2 devices):
symbol scratch=b27
symbol vExtraVar1=28 ' first byte above named variables
symbol vExtraVar2=29 ' 2nd byte above named variables
scratch = 1
poke vExtraVar1,scratch
scratch = 100
poke vExtraVar2,scratch
' now increment var1
peek vExtraVar1,scratch
inc scratch
poke vExtraVar1,scratch
' add 10 to var2
peek vExtraVar2,scratch
scratch = scratch + 10
poke vExtraVar2,scratch
(With X2 devices you can do the same thing with scratchpad using, for instance, the same symbol definitions, by replacing peek and poke with get and put.)
Yes, you can use the "extra" word variables, s_w1 - s_w6 (I'd reserve s_w0 ("task") and s_w7 ("time)).
You can also use the word variable bptr (and on x2 devices, ptr).
Many ways now to skin that cat.