Adding value from another text file

I have two text file. Text File A and Text File B

Text File A

T168
T169
T170C0.95F025S58H1000
T176
T250


Text File B

M48
METRIC,LZ
VER,1
FMAT,2
DETECT,ON
%
G93X0Y29
T250
X22Y0
X0Y0
T169
X016038Y11991
X203998Y11991
X203998Y-134725
X216888Y105277
X216Y-108
X003148Y105277
X004Y-108
T168
X216888Y105277
X216Y-108
X003148Y105277
X004Y-108
T170
X11Y1535
T176
X119035Y-126978
X024039Y-119104
X024039Y-120374
X024801Y-117961
X048118Y-124438


I want to copy the text file A and Insert the value In Text File B After the line FMAT,2
So that it wil look like this
M48
METRIC,LZ
VER,1
FMAT,2
T168
T169
T170C0.95F025S58H1000
T176
T250
DETECT,ON
%
G93X0Y29
T250
X22Y0
X0Y0
T169
X016038Y11991
X203998Y11991
X203998Y-134725
X216888Y105277
X216Y-108
X003148Y105277
X004Y-108
T168
X216888Y105277
X216Y-108
X003148Y105277
X004Y-108
T170
X11Y1535
T176
X119035Y-126978
X024039Y-119104
X024039Y-120374
X024801Y-117961
X048118Y-124438


There is any way to do this? Pls Help me

Thank you

I don't mean to be rude but you are posting around three or four questions every day all related to opening one file, manipulating the contents (usually by finding and replacing contents), and then writing out the results to another file.

All of them use exactly the same string and file manipulation methods.

Are you not taking in any of the answers and applying them to each new question?