Please direct the school to the following regulation:
8 CFR PART 1274a-CONTROL OF EMPLOYMENT OF ALIENS \ § 1274a.12 Classes of aliens authorized to accept employment\ § 1274a.12(c) Classes of aliens authorized to accept employment.
(9) An alien who has filed an application for adjustment of status to lawful permanent resident pursuant to part 245 of this chapter. Except as provided in §§ 1245.13(j) and 1245.15(n) of this chapter, employment authorization shall be granted in increments not exceeding one year during the period the application is pending (including any period when an administrative appeal or judicial review is pending) and shall expire on a specified date. For purposes of section 245(c)(8) of the Act, an alien will not be deemed to be an “unauthorized alien” as defined in section 274A(h)(3) of the Act while his or her properly filed Form I-485 application is pending final adjudication, if the alien has otherwise obtained permission from the Service pursuant to 8 CFR 274a.12 to engage in employment, or if the alien had been granted employment authorization prior to the filing of the adjustment application and such authorization does not expire during the pendency of the adjustment application. Upon meeting these conditions, the adjustment applicant need not file an application for employment authorization to continue employment during the period described in the preceding sentence;
Please see: http://www.uscis.gov/ilink/docView/SLB/HTML/SLB/0-0-0-1/0-0-0-11261/0-0-0-39749/0-0-0-39967.html
This link (above) discusses the ability of an individual to accept employment after filing adjustment of status. Individuals in Adjustment proceedings are accorded the same privileges that accrue to a Permanent Resident. It is also sufficient to attend school. You should discuss this matter with the Designated School Official (DSO) in the International Student Office. I am sure they will be able to provide proper input to the admissions office.