Dynamic Connection Strings In SSIS

Possible or not? -->
I maybe lazy - but I want to achieve just specifiying 1 variable in SSIS package ("environment") - and all the connectionStrings should "poof" magically be adjusted to correct locations

In DTS I created a SetDTSenvironmentVariables function for all my packages - so how wouldIi achieve this in SSIS?

Function SetDTSenvironmentVariables( environment )
Folder = "MyDtsPackageFolder"
Select Case environment
case "DEV"
DTSGlobalVariables("WorkingDirectory").value = "C:Packages" & Folder
case "STAGING"
DTSGlobalVariables("WorkingDirectory").value = "D:Sql_working_directoryMy_productionSTAGING" & Folder
case "LIVE"
DTSGlobalVariables("WorkingDirectory").value = "D:Sql_working_directoryMy_production" & Folder
End Select

'
' Set Connection Properties
'
dim oPackage, oConn
set oPackage = DTSGlobalVariables.parent
oPackage.LogFileName = DTSGlobalVariables("WorkingDirectory").value & "LogsErrors.txt"
For Each oConn In oPackage.connections
Select Case oConn.Name
case "My_DB"
Select Case environment
case "DEV"
oConn.datasource = "SERVER01"
oConn.Catalog = "My_Production"
case "STAGING"
oConn.datasource = "SERVER06"
oConn.Catalog = "My_Staging"
case "LIVE"
oConn.datasource = "SERVER06"
oConn.Catalog = "My_Production"
End Select
case "Schools.xls"
oConn.datasource = DTSGlobalVariables("WorkingDirectory").value & "" & "School_Codes.xls"
case else
oConn.datasource = DTSGlobalVariables("WorkingDirectory").value & "" & oConn.Name
End Select
Next

set oPackage = nothing
set oConn = nothing
End Function