Constraining it by determining how many cycles the AI can use to process how to go about making paper clips, plus some spacial restriction (don't touch anything outside this area) plus some amount of energy to be spent restriction (use up to X energy to create 10 paperclips) would help. Allowing for levels of uncertainty such as 89 to 95% certain that something is the case would help.

However very similar suggestions are dealt with at length by Bostrom, who concludes that it would still be extremely difficult to constrain the AI.