You could use

=IF(ISNUMBER(MATCH(F3,data!$B$3:$B$99,0)),VLOOKUP(F3,data!$B$3:$B$99,1,0),"")

but if truly only want the agent number (which is the same as in column G), then:

=IF(ISNUMBER(MATCH(F3,data!$B$3:$B$99,0)),F3,"")

would do it.