Haplogroup Helps Define Ethnicity

I had another DNA test done to test my haplogroup through what is called Deep Clade testing.
It is basically to work out where your y chromosome originated from.
My result is R1b1b2a1b5 (or shorthand R-L21+ due to the marker that returned positive).
Does not look like much but this haplogroup has its origins in Ireland, Scotland and Wales.
So know when people say that I look Celtic I can confirm that my ancestors were indeed Celtic.

As for using this information to identify a potential father;
I could use this info to narrow down the medical student names to those that are of Irish, Scottish or Welsh descent. Although problems could arrise if there was any infidelity in these families. Or if they had migrated hundreds of years ago to somewhere else in europe before coming to Australia and subsequently their name may have changed somewhat in these other locales.
BUT it does give me something else to work with and it gives me a sense of belonging to a region.
While I do not have a definitive result of a more specific region or ethnicity (which is nearly impossible anyway) I am pretty happy about this result.
I have something more tangible than I had previously.