How to 'Point' a matrix?

I've nicked some of trinity's matrix stuff for the basis of v2's entity system. It's working fine, with sub-entities etc, but I really need to figure out how to point a matrix towards a point in 3d space.

Any links or tutorials or even code that cover this or anyone here know?

Here's the matrix code as is, fairly simple, but works.

Type Matrix
	
	Method New()
	
		Mat=New Double[16]
			
	End Method
	
	Method Delete()
	
	'	Release Mat
		Mat=Null
	
	End Method
	
	Method Identity()
	
		Local Index:Int
		
		Mat[ 0 ] = 1
		For Index=1 To 15
			Mat[ Index ]=0
		Next
	
	End Method
	
	Method Pitch( nPitch:Double )
	
		Self.Identity()
		mat[5]=Cos( nPitch )
		mat[6]=Sin( nPitch )
		mat[9]=-Sin( nPitch )
	    mat[10]=Cos( nPitch )
	    mat[15]=1
	
	End Method
	
	Method Yaw( nYaw:Double )
	
	   Self.Identity()
		mat[0]=Cos( nYaw )
		mat[2]=-Sin( nYaw )
		mat[5]=1
		mat[8]=Sin( nYaw )
		Mat[10]=Cos( nYaw )
	
	End Method
	
	Method Roll( nRoll:Double )
	
	   Self.Identity()
		mat[0]=Cos( nRoll )
		mat[1]=Sin( nRoll )
		mat[4]=-Sin( nRoll )
		mat[5]=Cos( nRoll )
	
	End Method
		
	Method Position( nX:Double,nY:Double,nZ:Double )
	
		Self.Identity()
		mat[0] = 1
		mat[3] = nX
		mat[5] = 1
		mat[7] = nY
		mat[11] = nZ
		mat[15] = 1
	
	End Method
	
	Method Copy( IN:Matrix)
	
	   Local Index:Int,Val:Double
	
	   For Index=0 To 15
		Mat[Index]=IN.Mat[Index]
	   Next	
	
	End Method
	
	Method Rotate( nPitch:Double,nYaw:Double,nRoll:Double,X:Double=0,Y:Double=0,Z:Double=0 )
		
		Self.identity()
		Local Temp:Matrix = New Matrix
				
		Self.Pitch( nPitch )
		Temp.Copy( Self )
		Self.Yaw( nYaw ) 
		Temp.Multiply( Self )
		Self.Roll( nRoll )
		Temp.Multiply( Self )
		Self.Position( X,Y,Z )
		Temp.Multiply( Self )
		
		Self.Copy( Temp )
		
	End Method
		
	Method TForm_Point( X:Double,Y:Double,Z:Double )
	
		tFormX = (mat[0] * X) + (mat[1] * Y) + (mat[2] * Z) + mat[3]
		tFormY = (mat[4] * X) + (mat[5] * Y) + (mat[6] * Z) + mat[7]
		tFormZ = (mat[8] * X) + (mat[9] * Y) + (Mat[10] * Z) + mat[11]
	
	End Method
	
	Method TForm_Point2D( X:Double,Y:Double )
		
		Local Z=0
		tFormX = (mat[0] * X) + (mat[1] * Y) + (mat[2] * Z) + mat[3]
		tFormY = (mat[4] * X) + (mat[5] * Y) + (mat[6] * Z) + mat[7]
		
	End Method
	
	
	
	Method Multiply( With:Matrix )
	
		Local Temp:Matrix = New Matrix
		Local M:Int,m1:Int,m2:Int
	
		For m=0 To 3
			For m1=0 To 3
				Temp.Mat[ m1*4+m]=0
				For m2=0 To 3
					Temp.Mat[ m1*4+m]:+With.Mat[m2*4+m]*Mat[m1*4+m2]
				Next
			Next
	   Next
	
	   Local Index:Int,Val:Double 
	
	   For Val:Double =EachIn Temp.mat
		Mat[Index]=Val
		Index:+1
	   Next
	   'Release Temp
	
	End Method
	
	Method Debug( PrintFunc:Int(Out:String) )
		
		For Local J=0 To 15
			
			printFunc (J+1)+":"+Mat[J]
			
		Next
			
	End Method
	
	Field Mat:Double[]
	Field tFormX:Double,tFormY:Double,tFormZ:Double,tW:Double
End Type