Name of wave and wave scalling

I'm beginner in IGOR and working on analysing of data of photoemission spectra.

I don't know how I can read string variable from source file

set scale (X) by first column from source file(As I know it's impossible with function SetScale)

String xName = StringFromList(0, S_waveNames);  // S_waveNames is set by LoadWave
String yName = StringFromList(1, S_waveNames);  // S_waveNames is set by LoadWave
Wave xw = $xName  // Create wave reference for X wave
Wave yw = $yName  // Create wave reference for Y wave
Variable x0 = xw[0]
Variable dx = xw[1] - xw[0]
SetScale/P x x0, dx, "units", yw  // Change "units" to whatever is appropriate for your data
KillWaves xw  // We no longer need the X wave

SetDataFolder root:ARGUS:Load_Files	
FolderName=FolderName+stFileName+stFileName1
Open/R/P=$FolderName RefNum
FReadLine/N=45 RefNum, NameCoreLevel
Close RefNum
end

#pragma rtGlobals=3		// Use modern global access method and strict wave access.

// Add an item to Igor's Load Waves submenu (Data menu)
Menu "Load Waves"
	"Load Sergey Text File...", LoadSergeyTextFile("", "")
	"Load All Sergey Text Files In Folder...", LoadAllSergeyTextFiles("")
End

Function GetWaveNames(refNum, xName, yName)
	Variable refNum
	String &xName				// Output
	String &yName				// Output
	
	xName = "tempXWave"				// X wave will be killed after scaling is set on y wave
	
	String text, format
	
	// Read file name from first line of file
	FReadLine refNum, text				// Read first line
	format = "# Transition %[^/]"		// Skips "# Transition " reads text until slash"
	sscanf text, format, yName			// Extract y wave name
	
	// Clean up y wave name so it is a standard Igor name as liberal names are harder to program with
	yName = CleanupName(yName, 0)
		
	return 0
End

//	LoadSergeyTextFile(pathName, fileName)
//	Loads y wave into current data folder.
//	NOTE: If the wave already exists in the current data folder, it is overwritten.
//	pathName is the name of an Igor symbolic path or "".
//	fileName is one of the following:
//		The name of a file in the folder designated by pathName.
//		A partial path from the folder designated by pathName to the file to be loaded.
//		A full path to the file to be loaded.
//		"" to get an Open File dialog.
//	The required file name extension is ".txt".
Function LoadSergeyTextFile(pathName, fileName)
	String pathName			// Igor symbolic path name or "" for dialog.
	String fileName				// file name, partial path and file name, or full path or "" for dialog.
	
	Variable err

	// This puts up a dialog if the pathName and fileName do not specify a file.
	String message = "Select a Sergey text file"
	Variable refNum
	String fileFilters = "Sergey Text Files (*.txt):.txt;"
	Open /R /Z=2 /P=$pathName /F=fileFilters /M=message refNum as fileName
	
	// Save outputs from Open in a safe place.
	err = V_Flag
	String fullPath = S_fileName

	if (err != 0)
		return err			// -1 means user canceled.
	endif
	
	String xName, yName
	err = GetWaveNames(refNum, xName, yName)
	// Print xName, yName	// For debugging only

	Close refNum

	if (err != 0)
		return err			// Error in GetWaveNames 
	endif
	
	String columnInfoStr = ""
	columnInfoStr += "N='" + xName + "';"
	columnInfoStr += "N='" + yName + "';"
	
	// Load the data using Load General Text (/G)
	LoadWave /G /A /O /D /B=columnInfoStr /Q fullPath

	Wave xWave = $xName
	Wave yWave = $yName
	
	// Set X scaling
	Variable x0 = xWave[0]
	Variable dx = xWave[1] - xWave[0]
	SetScale/P x x0, dx, "nm", yWave  	// Change "nm" to whatever is appropriate for your data
	
	KillWaves/Z xWave					// X wave is no longer needed
	
	Printf "Loaded %s\r", yName

	return 0			// Zero signifies no error.	
End

//	LoadAllSergeyTextFiles(pathName)
//	Loads all .txt into the current data folder.
//	NOTE: If a wave already exists, it is overwritten.
//	See LoadSergeyTextFile documentation above for details.
Function LoadAllSergeyTextFiles(pathName)
	String pathName	// Name of an Igor symbolic folder created by Misc->NewPath
	
	if (strlen(pathName) == 0)
		String message = "Select a directory containing only Sergey data files"
		NewPath/O/M=message SergeyDataPath		// This displays a dialog in which you can select a folder
		if (V_flag != 0)
			return V_flag							// -1 means user canceled
		endif
		pathName = "SergeyDataPath"
	endif
	
	Variable err = 0

	String fileName
	Variable i = 0
	do
		fileName = IndexedFile($pathName, i, ".txt")
		if (strlen(fileName) == 0)
			break										// No more files
		endif
	
		err = LoadSergeyTextFile(pathName, fileName)
		if (err != 0)
			return err
		endif
	
		i += 1
	while(1)
	
	return 0
End