(1) P.L. 86-272 specifically applies, by its terms, to "interstate commerce" and does not directly apply to foreign commerce. Montana will apply the provisions of P.L. 86-272 and the rules found in this sub-chapter to business activities conducted in foreign commerce. Therefore, whether business activities are conducted by:
(a) a foreign or domestic company selling tangible personal property into a country outside of the United States from a point within Montana; or
(b) either company selling such property into Montana from a point outside of the United States, the principles under this statement apply equally to determine whether the sales transactions are protected and the company immune from taxation in either Montana or in the foreign country, as the case might be, and whether, if applicable, Montana will apply its throwback provisions.