hi
if u r using winzip, it is not possible with the usual version. u need another version called professional or classic or something(i dont remember, check winzip site). with that u can specify a program that'll run when the unzipping is over.
if u r trying to distribute ur program, use some packaging wizard like install shield, or the padkage & deployment wizard that comes free with visual basic.
hope i helped u.
luv
Karthik.