Should Kohanim Was Their Hands?

I am a Kohen. If I am not allowed to move from my place while standing during the chazarath hashatz, then how do I wash my hands in preparation for birkath hakohanim?

This is an excellent Question. Firstly, one must remember that so long as one has not had a hesech hadaath from one’s hands after netilath yadayim then one may rely on the netila which one did in anticipation of tefillath shacharith in the morning. If one has had a hesech hadaath then one must again do the netillah with a bracha. However, as your Question implies, the time for doing so is not during the chazarath hashatz, but rather at some earlier point.