First, HMDA applies to commercial loans to purchase, improve or refinance dwelling secured loans. Read the definition of "dwelling" in Reg C and it's Commentary:
Dwelling means a residential structure (whether or not attached to real property) located in a state of the United States of America, the District of Columbia, or the Commonwealth of Puerto Rico. The term includes an individual condominium unit, cooperative unit or mobile or manufactured home. [§203.2(d)]
The definition of “dwelling” is not limited to the principal or other residence of the applicant or borrower and thus includes vacation or second homes and rental properties. A dwelling also includes a multifamily structure such as an apartment building. Recreational vehicles such as boats and campers are not dwellings for purposes of HMDA. [Commentary to §203.2(d) #1 & #2]
Second, HMDA does not apply to the scenario you describe as it is not a dwelling purchase, improvement or refinance.