You may try:

dim WD As WOrd.application
set wd = new word.application
wd.documents.open ("document path")
wd.visible = true
..
..
..
If Cells(i,1)="OK" then
WD.selection.font.name = "target font"
WD.Selection.Font.Size = 10
End If

i am not able to print to doc by using your code,
i have tried the below way but changes are reflecting in excel  instead of
word.....
Kindly check the below code and suggest
'***********************************************************************

Sub king()
fileNum = FreeFile()
cValStr = "Test case is passing"
Open "C:\Documents and Settings\naseemahmed_shaik\Desktop\try.doc" For Output
As fileNum
With Selection.Font
.Name = "Trebuchet MS"
..Size = 12
End With

Print #fileNum, cValStr '************************** here i want cValStr to be
printed in "Trebuchet MS"***************
Close #fileNum
Close #try
End Sub