Hi,
I finally ended up getting a very inexpensive numeric keypad to try with a laptop /Omb software.
It appears to work really well.
Mine has 18 keys, 14 of which are useable to assign variations , intro's fills etc.
As for the remaining 4 , 1 is for numeric lock another 2 are used for switching back & forth to Preset & 4th unfortunately can't be assigned to anything.

Either way, having 14 assignable keys should be enough for me to be able to swith between the various fills , variations etc.

Beats having my laptop perched on top of a piano or keyboard.

best wishes
Rikki