That sp MUST be run against the publisher database

use PublisherDBName;

GO

EXEC EXEC sp_reinitsubscription

@publication = N'MCSTST7',

@subscriber = N'ODDBMSREPT02\ODDBMSREPT02',

@destination_db = N'RPTMCSTST7',

@invalidate_snapshot = 1;

or

EXEC PublisherDBName.dbo.EXEC sp_reinitsubscription

@publication = N'MCSTST7',

@subscriber = N'ODDBMSREPT02\ODDBMSREPT02',

@destination_db = N'RPTMCSTST7',

@invalidate_snapshot = 1;