Piggy Back

Can you buy a round trip ticket and expense it?

You have the bank. All in the same bid month.
End a pairing on the 21st, ticket home on the 22nd, MEM to XYZ.
Begin a pairing on the 29th, ticket XYZ to MEM on the 28th.

So roundtrip ticket MEM-XYZ-MEM. Each travel day is within 3 days of a trip pairing.

I have always done one way tickets, but have been looking at round trips. They would be cheaper and save money. Can I expense this type of deviation?