Add foot pedal to a Dremel

thankyou john, i have one more question,

can you then adjust the dremel speed to 5 or 4 or 8 and then use
the footpedal from 0-4, or 0-8??,

The Dremel speed control electronic circuit requires an AC current
and can be damaged or malfunction by being fed chopped up AC
current from the foot speed control. 

ok then, something else that i have done is to use a dial speed
control made for flexshafts and a pedal together to acheive the same
results as above, might you tell me the safest way that this must be
done???, like i said i am trying to use the pedal in different
situations of carving and sanding where i can control the top speed
and have the pedal go from 0 to that speed, dave