Have to understand the scriptures were written in sematic (aramic, hebrew) languages not english. Semetic names often mean something Isacc or Yizkah could be translated into "one who laughs" or laughing one. Another example Ishmael is two words and could be translated into "listens the" or "God Listens". There are various variations of the name Muhammad that base word though is the letters H-M-D (HA - MEEM - DEL) which means "praised" or "to praise". Here is an article on H-M-D on wikipedia that describes how this base word is used in the various semetic languages.
So yes the name is found in the scripture lots of times but used as a word and not to refer to someone. There are occurances in the scripture were muslims claim the word is actually refering to a person. In the new testament there are several mentions of the conselor/advocator/spirt of truth that will come after.
The greek word is parakletos. In Aramic I guess this can be translated in to HA-HE-MEEM-DEL or machmad. On youtube there are probably 100s of videos of passion of christ scene where the actor playing Jesus is reading some from John 15:20 or so. Here they take the liberity of translating the word to aramic themselves. This is complicated because there are no original aramic copies of the new testament, oldest copies found are written in greek.
The other thing muslims mention is in old testament. There is a verse in the psalms song of solomon 5:16 where the word HA-HE-MEEM-DEL-LAMED-HA-MEEM is used. In the english translations of this is translated as "altogether lovely". This english translation is not really correct as this is the word HA-HE-MEEM-DEL is plural form.
An example of this is Elohim, the third word in the Genesis, in english this word is obviously just translated to God but it is actually a plural form of Eloh (A-L-H). When it is used in the bible though the nous is plural but the verbs are singular. I think this is called a royal noun? On wikipedia they talk about it depth.
This is unlikely that a form of language used to describe God is used to describe a person. Muslims add in to this claim the context of the usage. The main claim for evidence of Muhammad in the bible (which you were probably getting at) presented by muslims is the 10000 saints prophecy. This is mentioned a couple times in the old testament.
Deuteronomy 33: 2
Isaiah 42: 1-13
Habakkuk 3: 3
Muslims believe that MT Paran where Abraham brought Ishmael and Hagar is somewhere around their two holy cities Medina and Mecca which may or may not be right. They claim these mentions of arab sons/tribes (nebaioth, tema, kedar) and mention of 10000 saints coming down MT Paran is the description of Muhammad taking over the city of mecca from the idol worshippers. They have some books other than the their main book that I am not to familiar with where the actual mention 10000 saints being lead down a mountain or something.
Muslims also claim the description of this man matches a description of Muhammad given in a book written by someone who was alive at the time. If you read 5:10-5:16 it says best of 10K, describes man like it says it their muslim books, and then "he is Muhammad(s)". So here they are saying look in addition to our prophecy it also calls him out by name. When reading from start to finish though this is actually a sheep herding girl describing here love.
So in summary yes the name is also a common word that is used lots in the scripture. Does it refer to a person? In almost all cases no and in some places it has been questioned but there is no place where it is 100% clear the word is refering to a person.