T4 dynamic include directive - t4

Question

I'm using T4 to generate some scripts as runtime templates. A part of this is to read some text files that include some T4 directive the for each file generate an output using a master template.
Each file may contain text such as:
Create table foo (
rid bigint identity(<#= db.DefaultSeed #>, <#= db.DefaultIncrement #>),
...other table specific stuff
I have a template that includes the object data for the db referenced in the other files and some source file reference.
The main template to run could be like:
<## template language="C#" #>
<## assembly name="System.Core" #>
<## import namespace="System.Linq" #>
<## import namespace="System.Text" #>
<## import namespace="System.Collections.Generic" #>
<## include file="Src" #>
Where src would refer to a variable passed to the template.
Then I would like to have a string list of files that could be iterated over to build individual scripts so that the following could be done in say a console program:
public void BuildTables(){
List<string> files = getFiles();//just get a list of files in a folder to process
foreach(var f in files){
var mainTemplate = new MainTemplate(dbSettings);
mainTemplate.Src = f;
String text = mainTemplate.TransformText();
System.IO.File.WriteAllText(outPath + f, text);
}
}
Howerver, it looks like the include directive is unable to accept variables like:
<## include file="<#= Src #>" #>
Is there a way to inject the text into the template file?