import file without .py into another module

[kevinbercaw at gmail.com]

I have a python script that accepts two arguments:
sys.argv[1] is the full directory path to a config script.  The script is python but does not have a .py extension!
sys.argv[2] is the file name of the config script

For example:
mainScript.py ./ a15800


The config script sets variables that I want to be able to use in the main script.

*** contents of "a15800": ***
myVar = "hello"

*** contents of "mainScript.py": ***
def printVars(configModuleName):
    myVarName = ("%s.myVar" % configModuleName)
    print "myVarName = %s" % myVarName
    myVarValue = eval(myVarName)
    print "myVarValue = %s" % myVarValue


if __name__ == '__main__':
    import sys
    import imp
    filePath = sys.argv[1]
    fileName = sys.argv[2]
    configModuleObject = imp.load_source(fileName, filePath)
    configModuleName = configModuleObject.__name__
    print "configModuleName = %s" % configModuleName
    printVars(configModuleName)

*** Output: ***
>mainScript.py ./ a15800
configModuleName = a15800
myVarName = a15800.myVar
Traceback (most recent call last):
  File "mainScript.py", line 27, in <module>
    printVars(configModuleName)
  File "mainScript.py", line 15, in printVars
    myVarValue = eval(myVarName)
  File "<string>", line 1, in <module>
NameError: name 'a15800' is not defined

*** Question: ***
How do I get the value of the config file variable "myVar"??  It seems it's interpreting the variable name as a string rather than a variable name.  I don't see any python function stringToVariable.