unable to set compnay name as the firstname of shipping/billing address

trying to extend sapcustomer extension and set the company name as the firstname of both shipping and billing adress. but the target is still not picking up and no "firstname" in the impex generated target

<item>

<type>CompanySalesUnitAddress</type>

<exportCode>Address</exportCode>

<description>Address of the company sales unit.</description> <canonicalItemSource>CanonicalPartyRelationshipSales</canonicalItemSource>

<updatable>true</updatable>

<attributes>

<attribute>

<name>firstname</name>

<transformationExpression>resolve('CanonicalAddress', 'SAPCUSTOMER_INBOUND_POOL', 'addressId='+#root.relatedPartyId+'_0001').companyName</transformationExpression> <exportCode>firstname</exportCode>

</attribute>

</attributes>

</item>

Please help