Data Input using VBA excel forms

i have currently made a form using excel see below
forms.jpg
i would like to create a code that would use the textbox1 and textbox2 as search criteria
and then for it to insert the data in textbox3,4 and 5 into required cells

for example
textbox 2 to search for the worksheet for requested Vehicle Reg then
textbox 1 to search for the cell with the exact date already inserted then
for the data in textbox3 to be written in B4
for the data in textbox4 to be written in C4
and for the data in textbox5 to be written in E4

in any one sheet per vehicle i have 365 days
and i have a total of about 51 vehicles

any help would be greatly appriciated

the code i have already for the ok button is as below,

Private Sub UserForm_Initialize()
    Dim TodaysDate As String
    
    TodaysDate = Format(Now(), "dd/mm/yyyy")
    
    TextBox1.Value = TodaysDate
End Sub

Private Sub cmdOK_Click()
    Dim x As Integer
' Check user input
    If TextBox2.Text = vbNullString Then
        MsgBox "please enter Vehicle Reg.", vbExclamation, "Vehicle Mileage"
        TextBox2.SetFocus
        Exit Sub
    End If
    If Not IsNumeric(TextBox3.Value) Then
        MsgBox "The Start Mileage Should Be A Figure.", vbExclamation, "Vehicle Mileage"
        TextBox3.SetFocus
        Exit Sub
    End If
    If Not IsNumeric(TextBox4.Value) Then
        MsgBox "The End Mileage Should Be A Figure.", vbExclamation, "Vehicle Mileage"
        TextBox4.SetFocus
        Exit Sub
    End If
    If Not IsNumeric(TextBox5.Value) Then
        MsgBox "The Fuel Should Be A Figure.", vbExclamation, "Vehicle Mileage"
        TextBox5.SetFocus
        Exit Sub
    End If
    
MsgBox "Data Input Complete"
' Clear the form
    For x = 2 To 5
    Me.Controls("TextBox" & x).Value = ""
    Next x
End Sub

again any help would be greatly appriciated