+1(514) 937-9445 or Toll-free (Canada & US) +1 (888) 947-9445
Yes

As long as:

1- Your status is legal in Canada

2- You only travel to the States and come back
 
http://www.cic.gc.ca/english/information/applications/guides/5256ETOC.asp

Check step 2.

You can enter canada multiple times from US on a single entry visa for canada.
 
i am from philippines though.i will be going to u.s. for interview in buffalo and will be back to canada.
thanks a lot for your help.