One way is to use the xp_cmdshell to call the DTS command line command. For instance, for the command line command...

DTS /Usa /Ppassword /Sserver /Npackage_name /Mpackage_password 

/A"SQLCatalog:8=dist" /A"SQLTable:8=dist.dbo.co" '

which uses two global variables that are char type (SQLCatalog and SQLTable), you would wrap the above statement in

xp_cmdshell  'DTS /Usa ...etc.'

You can also query a package using...

SELECT * FROM OPENROWSET('DTSPackageDSO',

'/Usa /Ppassword /Sserver /Npackage_name /Mpackage_password 

/A"SQLCatalog:8=dist" /A"SQLTable:8=dist.dbo.co", 'Select * from DTSStep_DTSDataPumpTask_1')

where the first argument ('DTSPackageDSO') is the provider info for DTS packages. It seems like performance is not great, but it may be due to the fact my packages refer to a non-sql database that is large.