My suggested approach is to parse the file as a general configuration file, and store things that look like assignments. If you have other weird stuff going on in your file, this may not work, but I think it will work here.
myvars = {}
# iterate through all the lines
for line in open('SampleText.txt').readlines():
# skip this line if it doesn't look like an assignment
if not '=' in line: continue
# split it into left and right pieces
left, right = line.split('=', 1)
# keep it around in a dictionary
myvars[left.strip()] = right.strip()
# now you can query it to get stuff:
myvars['efgh'] # returns /home/user/targetfile1.txt
open("sampleText.txt","r").read(). What part of reading a file is confusing? Or are you asking about finding the file name in a line of data? If so, what are the actual formatting rules for the line of data? It would help us if you could post the code you've written so far, so we know what part confuses you.